gl: Remove GLFW and reinstate FreeGLUT.

GLFW doesn't build on Visual Studio 2005 anymore, and I don't have time to keep
up with the changes.

So, we're switching back to FreeGLUT, which is more stable.

I've added the two missing features that made us switch to GLFW in the first
place: input methods and system clipboard support.

If MuPDF is compiled with our version of FreeGLUT, we now use these functions:

	* glutKeyboardExtFunc
	* glutSetClipboard
	* glutGetClipboard

2 files changed, 0 insertions, 0 deletions

diff --git a/thirdparty/freeglut b/thirdparty/freeglut
new file mode 160000
+Subproject 850d2102eb302bdd03fd81af6b6becdb1f3ae2e
diff --git a/thirdparty/glfw b/thirdparty/glfw
deleted file mode 160000
-Subproject 0ab0c5a5b9edf0fd0e1ecbee0c777b9a837564b