git: let links to git submodules be real links that can open in new tabs - not just in-page navigation Submodules should not be loaded with 'ypjax-link' because they point to a place outside the repository or maybe even outside the kallithea instance.

# 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
.