vcs: fix get_changesets to .reverse() list of revision hashes in place instead of using reversed() This is slightly more performant, and will also make CollectionGenerator work with reverse=True. Before, CollectionGenerator was used on get_changesets, but never with reverse option. Trying to use reverse, it would fail when applying len(): TypeError: object of type 'listreverseiterator' has no len()

# requirements.txt file for use as "pip install -r requirements.txt" as a
# readthedocs compatible alternative to "pip install -e ." which is a working
# alternative to "setup.py develop" which doesn't work with Mercurial 3.7
.