Adding PyQt5 compatibility (broken)

Adding compatibility for PyQt5 via a shim in Qt.py. This restructures the PyQt5 libraries
to match the layout seen in PyQt4, allowing it to continue to be used as drop in replacement.

This works up to the point of importing, however other API changes are broken - for example
the deprectation of .scale() on GraphicsItems throws an error currently.
Basic plot function works.
Adding some additional deprectated APIs for Qt5. Example plots (mostly) working.

This adds some remaining APIs that were deprecated in Qt5. These are easy to do
as they're all documented, e.g.
http://qt-project.org/doc/qt-5.0/qtwidgets/qgraphicsitem-compat.html

Tested with most of the examples. Although I can't be sure as I
don't know what the 'correct' output is, they look like they work.

Some issues with interaction e.g. on the color bar plot.
Merge branch 'pyqt5' of https://github.com/mfitzp/pyqtgraph into mfitzp-pyqt5
Generated qt5 template files
Add pyuic5 script (missing on ubuntu)
starting integration of pyqt5 functionality
Merge commit '100308' into pyqt5_rw

Conflicts:
	pyqtgraph/Qt.py
initial PyQt5 support via qt_backport