This reverts commit 9159362d.

- .from_pyvalue() now supports None

inspiral_lr: remove chads mass mode file in favor of Heather's population model file.  Additionally make sure that the iadd method can handle situations where not all objects have a population model specified, but force them to be the same if they do

inspiral_lr.py: remove the hardcoded 150 for horizon distance normalization and make a module level symbol

- add hacks (some of which might prove to be permanent) to filter out
  sub-threshold triggers, preventing them from contaminating the ranking
  statistic PDFs

- switch ranking statistic to this unconditionally for the October 2018
  open public alert test run.  after the test run and before O3 we will
  introduce more user-friendly plumbing allowing this to work with other
  template banks.
- NOTE:  git-lfs is used for any file ending in .hdf5 in the
  population_models/ tree

- NOTE:  a matching patch has already been pushed to glue, so all SnglInspiral
  row object types now provide the simulated attribute

- instead of a dictionary of SNRs and keyword arguments of (SNR,
  \chi^2/SNR^2) pairs, switch to a dictionary of SNRs and a dictionary of
  \chi^2/SNR^2
- this is the first step toward re-defining the ranking stat as the ln L
  maximized over subsets of triggers.  this re-organization will simplify
  the iterations require to implement that feature

Revert "Revert "inspiral_lr.py: Add population model to ranking statistic. Population model information in inspiral_intrinsics.py.""

This reverts commit 411d672e.

Revert "inspiral_lr.py: Add population model to ranking statistic. Population model information in inspiral_intrinsics.py."

This reverts commit 1cf67f62.

inspiral_lr.py: Add population model to ranking statistic. Population model information in inspiral_intrinsics.py.

- replace built-in algebraic model with the actual trigger distribution
  from all of O2, marginalized across the entire bank

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

dropped in online ranking statistic code

- Param elements now do support None, but not via the .from_pyvalue() method, yet, only via the .build() method.

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

- combine adjacent segments up to +/- 1 h from the trigger to estimate the trigger rate.
- this is a work-around for the situation in which vetoes slice up the SNR stream so badly that no triggers can be collected, even though very loud injections can still be recovered (which creates apparently impossible candidates)

- V1 must be removed from the coinc rates model in the denominator because
  all coincs will be made to be V1-less in the .__call__() method

- This reverts commit 8d438d4a.
- and fixes the feature
- the problem was start-up transients in the whitener leading to bad PSDs
  at the start of analysis jobs.  this was never a problem before because
  we were averaging over the entire experiment, but now the ranking
  statistic believes there is a brief period of insanely high sensitivity
  at the start of segments, and anything found during that time was given
  far too high a significance.  the fix is to have lloidparts check the
  n-samples property of the whitener that provides the PSD, and disregard
  PSDs until it gets close to the configured average-samples value.

- by finishing the construction of the dataless ranking statistic
- this makes gstlal_inspiral_fake_diststats obsolete, so it is deleted