New cmath element lpshiftfreq that reads in a complex stream and multiplies the phase by a constant without affecting the magnitude. This can be useful when a function whose phase is proportional to frequency has a known value at a particular frequency, and the user wishes to evaluate it at a different frequency.

 - bug fixes in lal_adaptivefirfilt
 - Implemented lal_adaptivefirfilt to correct for f_s and Q time-dependence
 - Added options to correct for complex kappas
 - Added EPICS bits to calib state vector

gstlal-calibration:  New element lal_adaptivefirfilt that allows constrution of a time-dependent FIR filter with zeros, poles, gain, and a time advance/delay. For details, type gst-inspect-1.0 lal_adaptivefirfilt.

gstlal_compute_strain:  Modified smoothing of f_s and Q to produce better results. Began updating CALIB_STATE_VECTOR for O3.

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

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

gstlal_compute_strain:  Added calibration line subtraction back in. There's also now a prototype function for subtraction of 60 Hz lines and harmonics, and for noise subtractions using witness channels.

- new package cmath: elements that perform unary operations and handle complex and real floating point arithmetic. Elements included are cabs, cexp, cln, clog, clog10, and cpow.
- new element lal_trackfrequency: base transform element that attempts to measure the loudest frequency in a signal.

- lal_smoothkappas: added filter latency option.
- lal_resample: simpler treatment of gaps. The complicated nonsense from before was unnecessary and messed things up.
- calibration_parts.py: function to remove lines and harmonics with a witness channel now works well.

- lal_complexfirbank:  Now handles latencies longer than filter length.
- lal_insertgap:  Compute offset when throwing away initial data as offset relative to the time when streaming started.
- calibration_parts.py:  remove_lines_with_witness should work now.

-the code needs to know how many input samples are needed to drain enough of the history for there to be nothing but 0s remaining.  to determine the amount of non-zero history, instead of counting contiguous non-zero samples from the start of the history count contiguous zero samples from the end and subtract from the total.

gstlal-calibration:  adjust gstreamer plugin .so filenames on gstreamer 1.14+ to work around changes to name mangling used by the plugin scanner

lal_transferfunction:  fixed off-by-one bookkeeping bug in storing old data, and property-setting bug

lal_transferfunction:  fixed Tukey window bug.  Also use comple conjugate when resampling transfer functions and going past the edges.

lal_transferfunction:  Made fir filter length independent of fft length. Added ability to resample and low-pass filter transfer functions to produce fir filters. Reduces noise in transfer functions wieh multiple witness channels are equally well correlated with the signal to be cleaned.

lal_transferfunction:  allow any length of fir filters by resampling the transfer functions. Reduce noise by low-pass filtering transfer functions.