- gstlal_inspiral_pipe and gstlal_svd_bank take as option
--sample-rate
 - the waveforms that are generated with a lower fhigh
are shifted forward such that all waveforms in a given
sub bank have a common amount of early warning
 - this has the effect that the actual fhigh of waveforms
is less than requested in a given sub bank, since the
waveforms are shifted according to the waveform that takes
longest to go from fhigh to ISCO

Signed-off-by: Surabhi Sachdev <surabhi.sachdev@ligo.org>

- and add a safety check for invalid IMR approximants

- filter allowed_rates with one loop

- make add_quadrature_phase a static method

A new table contains a link to a diff between the current HEAD of master
and the git hash at the time of review.

2) Add IMRPhenomC, SEOBNR_v2_ROM_DoubleSpin in
   the list of gstlal IMR approximants and remove
   IMRPhenomB, since it follows a different epoch convention.

Uses the function imr_time to over estimate waveform length.
Removes selection of sampling rates based on the ringdown frequency.
fixes #1895

templates.py: fix order of operation thinko in assigning the low frequency starting point for the chirptime calculation.  This fixes a bug introduced in 77050e5f which was meant to fix a corner case for IMBH waveforms.

templates.py: ensure that the second allowed rate is less than the ringdown frequency when choosing allowed rates for the LLOID time slice decomposition

templates.py: use imrchirptime to define the chirp length in order to be safe for imr waveforms, NOTE this will probably mean that there is effectively a bit more frequency padding per slice for the non imr waveforms, which shouldn't be a bad thing

don't override input built-in

templates.py: put the chirpt time calculation back into the time slice code.  I hadn't appreciated that this is obviously a slice dependent quantity that is not recorded in the XML

templates.py: don't do chirptime calculation in the time_slices() function, instead rely on template_duration to be set