Move to PyQt4.9

Generated python code by puyic4 is a bit cleaner, having translation in
the retranslateUI method, not in the main body.
Moved remove_shape method to ROI

Removing shape from shape list of the ROI was done by the remove_shape
of the interface, not the ROI object, which would cause trouble once the
interface is gone. Not that I will remove shapes without the interface,
but pew pew.
Included convex-capable point_in_poly method

Copied/pasted method to check if a point lies in, or on the borders of,
a concave or convex n-polygon. Raycasts and counts the intersections
with borders.