index: show repositories and repository groups in the same table Having two different tables with their own paging and search gave a bad UI. Instead, do like all other UIs that show directory content and show both "folders" and "files" in the same list. The rendering of repo groups is changed to use js data instead of a taking data from an html table. Repository groups are shoe-horned into the repository DataTable. The columns are no perfect match - some of the existing columns are thus given an empty default value.

# 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
.