Changed focus owner of LayerWidget to EDA_DRAW_PANEL_GAL to make keyboard events work (apparently everything works fine, to be tested more extensively).
Removed unnecessary event hook from EDA_DRAW_PANEL_GAL.

Smarter selection algorithm (does not allow to select both whole MODULE and its parts at the same time).
Cancel event works better (selection box does not appear after cancelling the selection tool).
Removed blinking selection box effect.
Model is accessed in more appropriate way (getModel() method).

More effective way of updating bounding boxes. IsCached() method made public. Removed some of unused fields from the layer description structure.

VIEW_ITEMs save the layer numbers they use, it allowed to speed up removal of items.

Added flipping mode.

Added generation of CancelTool event upon ESC key press.
Minor bugfix.

Changed reaction of SELECTION_TOOL to ToolCancel event (first event clears selection, second one deactivates the tool).