Add a version check for avcodec and swscale libraries.
Fix a bug in the xlib wiimote emulation button configuration. If you are using a mouse button for wiimote emulation you may need to adjust your settings.
git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@6426 8ced0084-cf51-0410-be5f-012b33b47a6e