Improved sceGeSaveContext/sceGeRestoreContext for external renderer: return error when core is busy.

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3430 4ab978e6-3352-0410-996c-0b42db0051c8
Fixed decoding of alpha values for DXT5 compressed textures in software rendering.

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3431 4ab978e6-3352-0410-996c-0b42db0051c8
Implemented native Atrac3+ decoding for Windows and Linux builds (experimental).

Applied small modifications to SettingsGUI layout.

Changed SAVEDATA encryption to be enabled by default.

Added option to extract SAVEDATA keys to tmp folder.

Removed changes from r3408 in VideoEngine.

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3432 4ab978e6-3352-0410-996c-0b42db0051c8