Small update for V7

Fix: Loading projects of V8 containing layer groups raised errors

Fix: When changing the second brush color in the color palette window then brush transparency was changed

Fix: If a tile map project was saved with spare frame enabled then loading that project caused an internal error

Fix: In rare cases a mouse wheel action can lead to an internal error

Fix: Palette file problems. Gimp palette can have either spaces or tabs to separate RGB values. PM only supported tabs, now also supports spaces.
JASC pal format added.

Fix: As soon as you change lock grid settings animation play back is broken. Wrong frames are displayed between the animating ones. Only closing software solved the problem.

Fix: Moving tiles in the tile palette not working with single image layers. When having single image layers in a tile map project then moving tiles in the palette is nor working correctly. It leads to wrong tile indices in the tile map.