BGE: New API method getDisplayDimensions

This patch adds a new API function to get the actual display dimensions in pixels.

Reviewers: dfelinto, sybren, lordloki, moguri

Reviewed By: lordloki, moguri

Differential Revision: https://developer.blender.org/D648

doc/python_api/rst/bge.render.rst

@@ -123,6 +123,12 @@ Functions
 
    :rtype: bool
 
+.. function:: getDisplayDimensions()
+
+   Get the actual display dimensions, in pixels, of the physical display (e.g., the monitor).
+   
+   :type dimension: list [width,heigh] 
+
 .. function:: makeScreenshot(filename)
 
    Writes an image file with the current displayed frame.