New features:
- based on a Qwt CVS snapshot later than Qwt-5.0.0rc0.
- supports Python-2.5 (requires a SIP snapshot or SIP-4.5 when released)
- support NumPy-1.0rc2
- supports Qt-4.2.0 (requires a PyQt4 snapshot or PyQt-4.1 when released)

