mdiff: move re-exports to top This style seems more common in our codebase.

test-commit-interactive-curses: remove unused import of parsers

strip: make tree stripping O(changes) instead of O(repo) The old tree stripping logic iterated over every tree revlog in the repo looking for commits that had revs to be stripped. That's very inefficient in large repos. Instead, let's look at what files are touched by the strip and only inspect those revlogs. I don't have actual perf numbers, since internally we don't use a true treemanifest, but simply iterating over hundreds of thousands of revlogs takes many, many seconds, so this should help tremendously when stripping only a few commits.

strip: move tree strip logic to it's own function This will allow external extensions to modify tree strip behavior more precisely.

manifest: remove unused property _oldmanifest The last use seems to have gone away in 7c7d845f8b64 (manifest: make manifestlog use it's own cache, 2016-11-10).

py3: convert key to str to make kwargs.pop work in mq The keys are passed here and there as unicodes and our transformer make things bytes. Due to that, mq was not poped and this results in error on Py3. Here we abuse r'' to make that str on Python 3.