Updated NSGL error tag.
Declared unnamed typedef structs as their types

Without defining them as structs it was impossible to forward declare `GLFWgammaramp` and `GLFWvidmode`.
Fixed _WIN32_WINNT not being set to Windows XP.
Merge pull request #121 from Systemcluster/patch-1

Declared unnamed typedef structs as their types.
Disabled stddef.h for GLFW_INCLUDE_NONE, cleanup.
Added support for mouse buttons 4-n.
Documentation fixes for glfwSetCursorPos.
Added workaround for legacy MinGW.

When building on legacy MinGW, WINVER and UNICODE need to be defined
before the inclusion of stddef.h (by glfw3.h), which is itself included
before win32_platform.h.
Conditionally define API version macros.
Workaround for libXi and CMake 2.8.7.
Updated menu label for minimization.
Fixed OS X cursor bugs #3, #72 and #88.
Removed unused flag.
Added description of 3.0.3 release.
Fixed Mac OS X bug where request for one fullscreen window blacks out other monitors
Added notes on swap interval defaults.
Added more detailed notes on some CMake options.
New theme for doxygen generated documentations.
Removed invisible element.
Merge pull request #141 from siavashserver/doxygen-theme

Added Doxygen documentation theme.