Pulling for the 0.5 release

Bright and early Monday morning I plan on pulling changes for the Bitcoin 0.5 release into tip-of-git. Expect some tip-of-git chaos and instability, I'm sure there will be issues to work through to move from wxwidgets to qt for the GUI.

I'd like to have a release candidate ready in a week or two, giving time for a week or two of testing, and have the 0.5 release available a month from now, assuming no major show-stopper bugs or network stability or denial-of-service or security vulnerabilities turn up between now and then.