ENH: Add DPI for Windows
ENH: Linux DPI support
FIX: OSX works
FIX: Fix for Python 2.6
FIX: Fix Py34 error
FIX: Unify subprocess calls
FIX: Fix examples test
FIX: Fix coveragerc
Added QtCanvas and QtSceneCanvas classes

Conflicts:
	vispy/app/tests/test_qt.py
Remove Qt backend embed method
flakify
test correction
testing fixes

Conflicts:
	vispy/util/config.py
Actually add the new Qt classes
testing fixes
Prettify backend selection
Merge pull request #567 from Eric89GXL/dpi

ENH: Query system for DPI
Merge pull request #562 from lcampagn/qtcanvas

QtCanvas
Use emulated double precision in mandelbrot
Merge pull request #563 from jdreaver/master

Use emulated double precision in mandelbrot