Win32 platform uses developers home directory for includes

The setup.py script contains the following config for Win32 targets:

elif sys.platform == 'win32':
ext_modules = [Extension("glfwpy.glfw", ["glfwpy/glfw.pyx"],
libraries=['glfw', 'opengl32'],
include_dirs=['C:\Users\dman\Desktop\glfw-2.7.6\include'],
library_dirs=['C:\Users\dman\Desktop\glfw-2.7.6\lib\win32']
)]

These should be made to reference a known path, perhaps relative to the glfwpy directory, and the README updated with where to place the GLFW C source.

Perhaps the best thing to do is include a copy of GLFW source inside the glfwpy project.