Converted back to entirely AWT/Swing based application.  Loses the
touchscreen, but has better performance
Added unused file for future reference
Fixed behaviour of linked view changes
Made sliders use discrete axis value where appropriate
Made caching shared amongst all models, and made number of threads
configurable
First attempt.  Has some caching and changes time/elevation without
flicker, but still has a layer within a layer.  Committing for a
save point if the next changes all go wrong...
Next pass.  Layers change elevation/time on request with no big redraw,
and no left-over tiles.

Also updated WorldWind libraries to latest nightly build, and added
support for more projections.

Still need to add a better cache (currently just using a HashMap)
Configurable image caching using EHCache now working.
Removed GPU caching, added EHCache and got mostly on-the-fly stuff
working.  Note that this seems to have a few issues from within Eclipse
(and possible on Linux in general), but works nicely on the video wall
which is what counts
Converted EdalDataLayer and EdalProfileDataLayer to implement NASA
WorldWind Layer objects (bringing them into line with the new version of
EdalGridDataLayer).  Removed (now unused) destroy method and changed
name of get/setElevation (clashed with MarkerLayer method).
Better info logging
Removed unused input class