This involves moving the NSDockTilePlugIn code to backend/taskbar
and fixing style to follow our coding conventions. One make target
was also renamed. All in all there is no change in functionality with this
commit.
This allows to start a recently played game directly from the dock. The
ScummVM.app application should have been permanently added to the
dock and the menu is only present when ScummVM is not running. The
list of recently played game is written by the taskbar code in ScummVM.
The Dock Tile Plugin only reads that list to populate the menu.
