gstlal_feature_extractor_pipe: changed segment splitting so that segments do not get shifted from segment_length arg given, added options in offline Makefile to request save and persist cadence, updated params to reflect more closely offline runs

lal_lpfilter:  new element that takes complex input representing amplitude and phase error of a signal at a particular frequency and computes a linear-phase FIR filter to correct this error.

gstlal_feature_extractor: changed use_kafka option to be part of save_format instead, to allow only one data transfer/saving option to run at a given time, fixed issue with hdf5 file saving where there were repeated timestamps, cleaned up finalization of saving features to disk when pipeline finishes, changed some default save/persist cadences

(patch mix-up.  needed in b185805c)

- add template_bank.xml.gz and template_ids.txt web services
- allows other processes to find gstlal_inspiral corresponding to a given template, or physical parameters.

- don't alllow "." or "-" characters.  prevents errors when used to construct T05whatever filenames and mDNS service names.

gstlal_feature_extractor: changed file saving to always persist features per persist_cadence rather than it being a feature for live data only. changed how features are pushed to kafka so that timestamps are aggregated correctly and depend on trigger time rather than buffer time

- get from gstlal.plotutil

plugin: lal_string_triggergen, trigger generator for string search

gstlal_compute_strain:  Use creal instead of splitting into real and imaginary parts and fakesinking (saves computational cost)

latency analysis, thus causing original snapshot files to continually be
overwritten instead of writing new files each snapshot

infrastructure

2. Temp. disabling fix/hack from docs makefile. I *think* it works now; not quite sure what gitlab is doing.
3. Adding offline tuturial makefile. currently the test is allowed to fail until we get it working.

Adding an example Makefile for running gstlal_compute_strain in O2, a filters file, and an example plotting script for O2

updated gstlal_feature_extractor + iDQ makefile with new gstlal opt build changes, added kafka proper as part of install, fixed some issues with C flags in kafka-python that caused install to fail

inspiral_lr.py: added None template_id to random_params because likelihood-ratio code requires it now