Added HiDPI support for retina display. Needs a patched glut framework available from http://iihm.imag.fr/blanch/software/glut-macosx/
Fixed newline
Merge branch 'master' of github.com:vispy/vispy

* 'master' of github.com:vispy/vispy:
  Pyglet backend emits an extra key press event when a 'text' key is pressed The first keypress event will have text set to empty string. If the key being pressed represents a character, a second event is emitted which has the right text, and key set to None.
  Use six.py throughout vispy
  Fixed issue #15: scroll events have x and y scrolling ev.delta is a typle with two floats
  Better mouse interaction in visual_test Line visual adds line-width capability