store.py: accept empty repos Fixes a traceback on the server side when trying to streamclone an empty repo (this was *not* introduced by 80e51429cb9a).

verify: only warn on copy nullid

make commit fail when committing unresolved files

Update win32mbcs extension * Code cleanup by Matt. * Fix the issue with case-insensitive fs support by wrapping also util.fspath() and util.checkcase() * Abort program when path conversion is failed.

Merge with stable

convert: implement startrev for hg source

merge with crew-stable