GitLab

- Remove obsolete directory "legacy"
- Remove obsolete branch "legacy"
- Order index functions consistently alphabetical
  in `setup.py`, `index_functions.py`, and `__init__.py`

This makes it easier to update the metadata with the newest version of the master table and also establishes a closer link with the master table by writing version information in the auto-generated metadata files.

This adds loading of multiple yml files from various locations.
Namely, in order, with later files taking precendence over earlier ones
the following directories are scanned for any .yml file.
The order of the files within each directory is standard globbing order.

- $PACKAGE/etc/
- /etc/climix/
- <XDG directories>/climix, including
- ~/.config/climix/