Popups can now be configured to stay or go when the user moves the mouse, refs: gemoose/geomoose#45
Fix paths in createSprite.py.  Add notice to output CSS.
Remove references to the all.gif sprite (in favor of all.png)

all.gif was used for IE6 compatibility and as we don't support IE6
anymore is no longer needed.  all.png was and remains the primary
version of the sprite.
Add reload toolbar icon and update sprite.
Merge branch 'master' into visible_layers_extension