1) Rename 'path' to outdir
2) Add detector names to the interferometer list filename
3) Make from_hdf5 method only be given a filename for simplicity

These can be used to estimate a posterior probability at some new point
given the set of samples stored in the posterior.

Resolve "Create single class that handles `duration`, `sampling_frequency`, `start_time`, `frequency_array`, `time_array`, and maybe `frequency_domain_strain`, `time_domain_strain`"

This renames all the cases of "prior" to "priors" in the gravitatinal
wave likelihood.

This reverts commit e577ba98

PriorSet -> PriorDict
BBHPriorSet -> BBHPriorDict
BNSPriorSet -> BNSPriorDict
CalibrationPriorSet -> CalibrationPriorDict

Introduced backports with deprecation warnings for the old classes