pre
Rewrote using a unified element lookup scheme (1 = H, 2 = He, etc.)
Improved/fixed the path handling code in the file load dialog.

0.73
.3 Improved the handling of background tasks (added queueing).
.3 Combined (and extended) the POVRay and OpenGL rendering setup dialogs.
.3 OpenGL rendering is now done in the main drawing area.
.3 Added an OpenGL cylinder drawing routine for B&S mode.
.3 Added a sin/cos lookup table for faster rendering.
.3 Added morphology facet labelling for OpenGL rendered images.
.3 Employed Gtk_Sheet to list morphology facets.
.3 Fixed a number of OpenGL related bugs.
.3 Trying to create a dialog window will now raise an existing one if available.
.2 Fixed the crystal morphology drawing bug.
.2 Fixed the povray crystal morphology rotation bug.
.2 Fixed the drawn cartesian axes (periodic models).
.2 Pruned genpos() for speed.
.2 partitioned the file read/write code (easier to maintain).
.2 Updates for GULP attachment energy calculation.
.2 use glib linked lists for bond and loaded model lists.
.2 changed mouse button events & selection handling (see gdis_manual.txt).
.2 added a workaround for execvp() flakiness on OS-X.
.1 rewrote lattice matrix code to match GULP more closely.
.1 rewrote unfragment molecules code, it's now much faster.
.1 implemented a new mechanism for running background jobs.
.1 implemented new scheme for atom status flags.
.1 added ability to add/remove single atoms (shift click) to selections.
.1 fixed some bugs in the molecular surface generation code.
.1 fixed some bugs (relating to shells) in the symmetry code.
.0 arbitrary surfaces can now be generated from a loaded unit cell.
.0 BFDH morphology can be predicted.
.0 Improved interfacing with GULP (eg Surface Energy calculation).
.0 improved GULP handling code (NB: only tested for version 1.4).
.0 added arrow buttons for changing the currently displayed model.
.0 added basic support for loading CIF files.
.0 Making selections in drag box & molecule pick mode is improved.
.0 hide/unhide implemented for selections.
.0 added option to change element type in the creator.
.0 default model orientation changed - z (not y) is now "up".
.0 labelled width & height in povray dialog.
.0 fixed a povray region lighting render bug.
.0 Added a button to create an OpenGL rendered window.
.0 Animation delay & frame stepping options implemented.

0.72
.5 fixed a problem with pixel_coord_map() for models > 0.
.5 repaired yet another gtk-crit problem in the model tree.
.5 repaired some core dumps related to the symmetry finding routines.
.4 partially (yhbw) implemented a 3D molecular/solvent surface calculation.
.4 added an option to force a model (eg a supercell) to the P1 spacegroup.
.4 tweaked selection and atom_info modes for slightly more sensible behaviour.
.4 changed the graphics font to a more standard type.
.4 repaired a gtk-critical warning relating to the model tree.
.3 added some drawing tweaks relating to atom site occupancy factors.
.3 better handling of the unfragment and constrain to pbc routines (for mols).
.3 better temporary file naming used during rendering.
.3 the .. dir should now always be present, even with insufficient permissions.
.3 eliminated some redundant model_ptr()/init_objs() calls.
.2 periodic table element colours are now immediately updated when altered.
.2 gulp input files with fractions for coords are now parsed properly.
.2 fixed a core dump that sometimes occurred when deleting a crystal habit.
.2 fixed a core dump when atoms that have an attached measurement are removed.
.1 adjusted the sky_sphere in order to render better looking crystals.
.1 improved handling of cut/paste/move atoms for fractional models.
.0 included code for point group/symmetry element determination & removal.
.0 expanded the number of loadable file types via babel conversion.
.0 crystal morphologies can now be rendered as solid glass like objects.
.0 nicer line styles are now used for morphology display.
.0 the model pane is now resizeable, and has hiddable rotation spinners.
.0 added model dependent pixmaps to the model tree.
.0 scaling is now done by pressing shift, LMB & dragging the mouse.
.0 prevented core dumping if environment vars PWD & HOME are not defined.
.0 proper cropping achieved via the GC clip mechanism.

0.71
 - rewrote the periodic image creation and constrain routines.
 - rewrote many of the loops and vector/matrix code.
 - added some code (scandir.c) to help with sun compilation.
 - fixed some bugs related to shell handling.
 - added support for dimension keyword in XTL files.
 - made periodicity dialog spinners remember the image numbers.
 - fixed a problem with rotation of any model numbered > 0.
 - fixed some glitches in the vdW surface area calculation.
 - ImageMagick's display is now the default viewer (instead of xv).
 - on startup, gdis now checks for optional executables & flags if not found.
 - added mem_shrink() function that frees (deleted) atom memory.
 - vdW/cova editing allowed in gperiodic dialog.
 - CPK scaling added to render dialog.
 - improved the handling of selections.
 - changes to the file load filter are now remembered.
 - fixed a crash that sometimes occurs when displaying space group info.
 - the rendered colours in region highlight mode are now correct.
 - added a 'complete molecules' option to the periodicity dialog.
 - added a wire frame thickness spinner to the render dialog.
 - the file mask is now visible in the load file dialog.
 - improved GULP job setup/handling.

0.70
 - more stuff saved to the gdisrc file
 - new interface look, with a tree display for model & assoc. properties
 - spruced up mdi to cope with new model/dialog manipulation schemes
 - implemented mouse & centroid position dependent rotation
 - implemented a centralized dialog creation/deletion scheme (request_dialog)
 - added space group lookup code (sginfo).
 - added morphology display code (cdd).

0.68
 - fixed (yet more) problem with centering some fractional models.
 - fixed some crashes that occur due to failed file loads.
 - added gperiodic code for prettier element viewing & colour editing.
 - implemented background rendering via fork().

0.67
 - fixed a problem with processing -ve surfvecs in MARVIN output files.
 - fixed a bug that sometimes prevented rendered images being displayed.
 - implementing option to render axes. (unfinished)
 - implemented VdW surface calculation and display/rendering codes.

0.66
- fixed offx/offy (no init!) bug which caused random errors in model drawing
- fixed a filename corruption error when editing element properties.
- added support for measuring torsional angles.
- added bond type support (at present - user must set the type)
  which is displayed & rendered appropriately.
- modified the creator to allow the user to set bond types.
- fixed a bug that could cause the element properties dialogue to core dump.
- box of colour and filename to aid editing element properties.
- template_model() routine to be applied on all new models, to
  do the necessary allocations.
- fixed a bug relating to data->geom not being allocated
  (ie no labels created) and thus core dumping when freed.
- fixed a rendering bug for periodic models (inverse x,y directions)
  and also a 2D rendering problem (degenerate cell frame cyclinders).
- added mvout & mvnout as recognised marvin output file extensions.
- added support for marvin output file parsing and also 2D
  periodic display.
- added a periodic image tool to the creator.
- implemented a more consistent method for creating and manipulating
  selections, plus you can now move and rotate a selection.
- implemented a revitalized geometric label creation dialogue.

0.65
- unleashed on the world.
