|SOURCE|
* Moved the Linux implementations of GLExtender and GLShader to the Common
  source directory, with the Linux-specific functionality retained in its
  respective source files
[Common::Arithmetic::Arithmetic]
* Un-commented the SIMDType global variable
* Removed comments about adding SIMD to scalar floating-point functions
[Windows::Renderer::WindowsRendererOGL2]
* Removed ToggleFullscreen (this should be handled in
  ZED::System::WindowsWindow)
* Stubbed-out the AddMaterial and GetMaterial nenber functions
* Removed the redundant window handle and device context, which is provided by
  the ZED::System::WINDOW_DATA structure
* GLExtender implemented as a pointer
* Fixed all references to the window handle and device context to the
  ZED::System::WINDOW_DATA's respective equivalents
* GLExtender constructed using the ZED::System::WINDOW_DATA in the class
[Windows::Renderer::WindowsRendererOGL3]
* TEMPORARILY DISABLED VIA "#if defined NOT_DEFINED" AT TOP OF SOURCE FILE
* THIS NEEDS TO BE RE-IMPLEMENTED
[Windows::Renderer::Camera]
* Removed entire source file, as it's implemented in ZED::Utility
Removed non-renderer specific member variables from WindowsRendererOGL2

|SOURCE|
[Windows/Renderer/WindowRendererOGL2]
* Removed member variables which are handled by the new Camera utility and are
  not directly tied to rendering specifically
[Windows/Renderer/WindowsRendererOGL3]
* Using the structs which are defined when setting them up instead of the
  struct definitions
[Windows/System/WindowsWindow]
* Create no longer sets the running member variable to true, as it is not
  guaranteed at creation time
Merge remote-tracking branch 'origin/window_manager' into window_manager
Merge remote-tracking branch 'origin/unstable' into window_manager

Conflicts:
	Source/Linux/Source/Renderer/GLExtender.cpp
Fixed issues related to integrating code changes with Windows

|SOURCE|
[Common/System/InputDevice]
* Using the ZED_WINDOWSYSTEM_WIN32 preprocessor directive for determining the
  course of action to take
[Windows/System/DataTypes_Windows_x86_32]
[Windows/System/DataTypes_Windows_x86_64]
* Win32 HANDLE used to typedef ZED_FILE_DESCRIPTOR and
  ZED_INVALID_FILE_DESCRIPTOR