[PyQt] PyQt v4.6 and SIP v4.9 Snapshots

[Phil Thompson]

The current PyQt and SIP snapshots are now driven from the v4.6 and v4.9
branches respectively. These implement the (selectable) incompatible API
changes described in the Roadmap.

You can now decide whether, for example, QVariant and/or QString should be
automatically converted to and from the corresponding Python types. The
default for Python v3 is to use the newer APIs, so I have updated the
installer for Python v3.1. All the demos should work with both Python v2
and v3.

I've decided not to look at individual methods to see if they should be
made more Pythonic - raising an exception rather than returning an error
flag for example. I don't think there are too many of these and they seem
to be in areas that duplicate standard Python - so if you want a more
Pythonic API then use the Python API. Happy to discuss further if somebody
wants to make a strong argument the other way.

Phil