Fixed the intereferences between fixed and user shortcuts.
Timeline: layers are now ordered from bottom to top

1. According to a lot of users, this new order of layers seems visually
clearer.
2. Fixed console error message: "Duplicate QLayout for
popupcolorpalette"
Merge pull request #202 from eVoLuTiVeMEDIA/master

Fixed some "interferences" between fixed and user shortcuts.