[PATCH 0 of 2] convert extension fixes

[Edouard Gomez]

Hello,

Here is a series of patch against crew that solves two bugs
with the convert extension:
 - tagging nodes should not use last revid in map file
   this leads to history corruption with incremental
   conversions (eg: when following an upstream svn project
   and working with a hg mirror)
 - cvs conversion requires ~/.cvspass existence.

Refer to the patches for better description.

Please apply.

-- 
Edouard Gomez