|BUILD CONFIGURATION|
[PandoraLinux]
* Added a ZED_WINDOWSYSTEM_X11 definition to use the correct window system
  types

|SOURCE|
[Common::Renderer::GLES2RenderTypes]
* Added OpenGL | ES 2.0 specific render types
[Common::Renderer::Renderer]
* Separated the Linux- and PandoraLinux-specific headers for OpenGL and
  OpenGL | ES 2.0
[Common::System::Window]
* Added PandoraLinux-specific WINDOWDATA information
[PandoraLinux::Arithmetic::Vector2]
* Fixed the assignment operator, which was not returning a reference before
|SOURCE|
[Common::System::Window]
* The WINDOWDATA type is determined by the windowing system in use by the
  platform
|BUILD CONFIGURATION|
[Linux]
* Added the ZED_WINDOWSYSTEM_X11 definition to the compiler's preprocessor
  definition flags