Making a montage script for autovars. Cloned from montage_script.py.

Edits and divergence forthcoming.
Added some useful documentation into the top-level docstring!
Serious re-writing. Two functions (untested) should be ~finished.

Removed most of the old material, replacing it with autovars-related stuff.

Use: gen_autovar_periodic_plots() and gen_autovar_nonper_lc().
Added an in-plot flag when an autovar is "strict".
Finished changes that made this compatible with autovars!