[SVN] New Revisions Window

[Michael Sheets]

Been working on a new revisions window and think I have it finished:

http://temp.whitefalls.org/revisions.png

Designed it for Mercurial but with the goal that it could be used in  
all the scm bundles. Adds a few options (A prompt, showing the target,  
button name), now uses the current document font for the log message,  
and formats the date. Has the same loading spinner as the old (not  
shown). Feedback?