Move fullscreen display resolution control to the GUI with the rest of the fullscreen toggling code. This removes redundancy of code that was in several places through the various video plugins. Unfortunately it means the fullscreen resolution setting also had to be moved to the main configuration dialog. I am sure that will meet some resistance.
Also added a window size setting for windowed mode.
Also pulled some X11 specific code out into a separate file.
git-svn-id: http://dolphin-emu.googlecode.com/svn/trunk@5395 8ced0084-cf51-0410-be5f-012b33b47a6e