Added in the ability to toggle mouse lock mode

By calling enabling mouse lock you are disabling the cursor.

Movement is still sent based on cursor movement from the center of the window.

There currently isn't a way to have the normal cursor with GLFW when you want to restrict the cursor to the current window.
A custom cursor could be draw at the virtual mouse coordinates.
Added the ability to poll a key state

Also removed the hideCursor parameter from ToggleMouseLock as it will hide it no matter what due to a short-coming of GLFW.