[PyQt] Incompatible Sip module version crashes Python

[Jim Crowell]

Over the last few months I've been upgrading a number of applications
from bindings created with SIP 4.7.3 to 4.12.2.

I notice that if I run such an app using the new bindings and it finds
the old SIP api module (sip.pyd on Windows), Python crashes.

I've added a bit of code to the Python wrapper module to explicitly
import sip and check sip.SIP_VERSION_STR against a required version, so
I can have it raise an exception and print an informative error message
instead of just crashing.

It would be nice if SIP behaved that way...

-Jim