Added test for MacBook Pro Retina display. See
http://forum.processing.org/two/discussion/2162/how-to-use-retina-displays-a-little-overview-and-performance-report-
for results.
Renamed P2DMapDisplay to Java2DMapDisplay. In Processing 2 both P2D and
OpenGL are OpenGL, but the default renderer (by calling size(x, y)
without third parameter) is Java2D.
Fixed gitignore to include Mac's hidden files.