[AD] Legacy fullscreen in Linux

["Trent Gamblin" <trent@xxxxxxxxxx>]

Going back a ways, Allegro's fullscreen mode doesn't work correctly with
modern compiz. Running in fullscreen on Ubuntu 14.04 (and earlier, not
sure how far back it goes), the dock and menu bar are always visible and
the Allegro window shows up in the area beside them, shifted so you can't
see XxY pixels (size of dockxsize of menubar.) Same thing happens on Mint
16 except with just the taskbar. It's visible in fullscreen mode and its
height is cut off from the Allegro window.

There's a workaround in compizconfig-setting-manager,
Utility->Workarounds->Legacy Fullscreen Support, so it seems whatever
Allegro does is "legacy".

Trent