Add option to enable/disable automatic menu bar items popup (related to issue #501)
Add Cmd+, and Ctrl+K keyboard shortcuts to open preferences
Fix #472 - Undo and redo change the size of spray tool
Arrow keys move the selection only when the current tool/ink is about selection

This fix a problem where arrow keys cleared the selection content when they
were used with a non-selection tool.
Remove unused variables
Add experimental option to flash the selected layer when Up/down array keys are used (fix #111)
Merge branch '1.0'