cleanup: remove dead code and templates related to 'Switch To' a33448d81f70 introduced a new 'Switch To' functionality and removed the last reference to branch_tag_switcher and thus to switch_to_list.html and the tags, bookmarks and branches pages. We don't need these pages ... and if we do, we will implement them differently. They are mostly YUI datatables with compare links that only can compare within the same kind of revision names.

# 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
.