histedit: miscellaneous style cleanups Fix some mis-wrapped lines, re-wrap some lines to be more compact, remove superfluous parens.

histedit: update docstring on histeditstate.read() The docstring showed the previous class-less heritage of read(). Now that it's classy, update the docstring.

histedit: remove now-superfluous repo argument from processreplacement Spotted by Olle on the mailing list during review.

histedit: move locks into state Allow action functions to control the locks. This is necessary for an implementation of x/exec or similar.

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.

histedit: pass state to action functions

histedit: pass state to processreplacement

histedit: pass state to boostrapcontinue Pass the state to boostrapcontinue and remove the unecessary passing of repo.

histedit: let the state expose a context but serialize correctly to nodes The histedit code often expects a context. However histedit hands around the tuple for the serialization and therefore hand over a parentctxnode. This leads to code having to return a context based on the parentctxnode. We let the state only return a context but correctly serialize and deserialze to a node.

histedit: add clear method to remove state Encapsulate the unlinking histedit-state and use the vfs layer instead of os.unlink.