[PATCH 0 of 8] convert-extension love: fixes, refactor, enhancements and svn backend

[Edouard Gomez]

More patches for convert extension.

The refactoring ones just move stuff around and fix the
dependencies.

Other patches implement some ideas i used to convert
successfully some repos:
 - add tags to a single branch that cumulates all .hgtags
   changes. I remember having submitted this before but
   i don't remeber the result of the review. So i submit
   it again
 - Add a mechanism for hand surgery of a cvs history. It
   simply is some new cvsps field that points directly the
   parent so we can fix cvsps mistakes when it gets the
   parent wrong.
 - Add the svn backend Daniel Holth coded on top of python
   SVN bindings. I can get fairly big repos converted
   (eg: ffmpeg, mplayer). This patch includes the fixes and
   enhancements from Brendan Cully.

-- 
Edouard Gomez