less: build custom Bootstrap from bootstrap.less instead of using plain upstream version - add current version of bootstrap to package.json dependencies - import bootstrap.less in main.less - remove bootstrap.css from root.html (the file will be removed later) bootstrap.js is still handled as before.

# 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
.