ZenGL 0.2.2

New bugfix release of stable branch.

Changelog:
- [Linux]now DIRECTORY_HOME will return $XDG_CONFIG_HOME
- [Linux]updated libjpeg to version 8c and built for compatibility with older distributives
- [Windows]fixed autopause under Windows 7 for minimized window via dockbar
- [Direct3D]now scr_Flush works as in GL-version
- fixed loading some wav's
- fixed file_GetExtension for situation when Directory has dot in name
- tex_Del won't delete zeroTexture, which is returns as a result of tex_LoadFromFile/tex_LoadFromMemory if texture can't be loaded