convert: rewrite tags when converting from hg to hg

convert: default revisions order depends on source When converting Mercurial repositories you expect the revision numbers to be preserved, while other sources conversions focus on efficiency.

convert: fail fast if source does not support --sourcesort

convert: add --sourcesort option for source specific sort Only supported by Mercurial source for now.

convert: parse sort mode sooner

convert: split toposort() into subfunctions for readability

run-tests: don't replace PYTHONPATH, just augment it. (Needed at least for Subversion bindings on OS X, which are in /opt/subversion. Useful for other external libraries installed in non-standard places too.)

merge with mpm

color: yet another typo

match: fold plan cases down to two special cases - merge always and match with patterns - make always and match with patterns the default - invert dostep3 to skipstep3 - move dirignore test inside exact case

walk: refactor walk plan - never is gone - reorder tests more cleanly - rename nomatches to exact for clearer semantics

match: remove match.never Only one user, can be translated to match.exact()

walk: use match.bad callback for filetype messages

match: ignore return of match.bad All users returned false, return can now be dropped