Moved the front-end project away from source/sdl/macosx/, so that Eternity can be built via cmake on OS X too.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2440 86ba831e-150c-0410-ab35-e06eaae15ed9
osx: added v_alloc files to Xcode project.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2441 86ba831e-150c-0410-ab35-e06eaae15ed9
Only set am_needbackscreen when vbscreen virtual aspect ratio is > 4:3

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2442 86ba831e-150c-0410-ab35-e06eaae15ed9