[PyQt] PyQt and Python v3

[Phil Thompson]

The current SIP and PyQt4 snapshots now support Python v3. The build
process is exactly the same - just use the right interpreter to run
configure.py.

pyuic4 has yet to be ported - but the code it generates should run under
Python v3.

pyrcc4 generates code for Python v2.6 and v3. If you need to generate code
for earlier versions of Python use the new -py2 flag. Note that Python v2.6
can handle both formats.

I'm still working through the examples - so far they have all run under
Python v3 without any changes.

Phil