histedit: read state from histeditstate
Read the state in histeditstate. This allows us to correctly update
internal variables when necessary without having to recreate a new
state. When we read a state in _histedit state while we will already
have state passed from histedit(), we can read the state in place
and don't have to merge two histeditstates.
To run the tests, do:
cd tests/
python run-tests.py
See http://mercurial.selenic.com/wiki/WritingTests for
more information on writing tests.