hgk: add repo root to window title

Forgot to quote "6^" in test-parentrevspec (see 94e77a174f55)

test-convert-hg-source: enforce conversion order with --date

convert: rename a class and a function

convert: mercurial_source: also search for copies in modified files There are some corner cases where we may have a copy in a file that isn't in the added list: - the result of a hg copy --after --force - after a merge across a (local) rename

convert: clear the dirstate before a conversion, invalidate it afterwards Clearing it before the conversion protects us from whatever data were there (file copies in particular). Invalidating it after the conversion avoids writing a possibly inconsistent dirstate to disk.