formula for glfw version OF is currently using. builds 64bit 32bit combo...

Formula for glfw version OF is currently using. builds 64bit 32bit combo on OS X. 
64bit needs to be added for windows.

@arturoc  - not sure if I am pulling from the right GLFW tree - let me know if it should be another one instead of https://github.com/arturoc/glfw/tree/feature-keysUnicode

Thanks!