make GLFW accessor const
fps accessors are now const
engine and glfw encapsulate an fps object
system.cfg can specify if the application is to run realtime (game style) or not (editor style)
GLFWwindow* associated with CDisplay* in CGLFW map (to make it easier to direct specific events to windows)
added glfw key handler to main glfw class to handle global key presses, and per display handlers to deal with specifics
viewport resize callback implemented
display now shows rotating triangle as proof of concept