- ignore instruments that haven't produced any triggers at all, because we
  wouldn't be worried about ranking those candidates anyway, but require at
  least one instrument to have produced triggers

doc Makefile: remove ignoring of __init__.py in gstlal/python, appears to trigger an AssertionError which is a known bug within sphinx

doc/Makefile: exclude gstlal/python/__init__.py from sphinx autodoc generation as this causes issues with building gstlal python documentation within gstlal proper

gstlal_feature_extractor: add dot graph for documentation, added separate groups for command line options, move imports around for aesthetics, change comment blocks (e.g. main) for documentation

Revert 9ac1b181

See merge request lscsoft/gstlal!1

This reverts commit 9ac1b181

gstlal_feature_extractor: propagated new waveform generation changes throughout, fixed some bugs/typos from switch causing pipeline to crash

- thinca() can now handle the cases where a ranking statistic has not been
  supplied but fapfar and/or min_log_L have been set.

- not currently used, but this plumbing will be needed to add source population models to the ranking statistic

- disable ln L assignment online until ranking statistic is sufficiently-well measured.  this is just a first hack to be better than nothing for the KAGRA testing being done.  it will surely be replaced by something else, later.

gstlal_feature_extractor: fixed bug in determining trigger time from buffer rows, now based on filter duration

idq_utils.py: changed implementation for generating sampled points for sine-gaussian and half-sine-gaussian waveforms

gstlal_feature_extractor_template_overlap + idq_utils.py: fixed bug in template generation causing missing templates, changed way templates are produced as a result, propagated changes to template validation code

gstlal_feature_extractor_template_overlap: added template bank overlap plot, aesthetic changes to html report

gstlal_feature_extractor_template_overlap: tweaked some plot params, added sampling of waveforms to plot to limit the number of waveforms plotted