Initial Xcode workspace & project support (4.6.3).
Updated .gitignore and ioquake3fe Xcode project.
Added Retina-enabled QUAKE III logo icon files.
Details in misc/xcode/xcode-readme.txt
Add bg_lib.h to Code::Blocks VM projects
Fix the speex Xcode project since it was missing its header search path.
Added "all game" and "all ioquake3" schemes to Xcode workspace so that they build properly.
Merge remote-tracking branch 'ioquake3/master'

Conflicts:
	.gitignore