Codes for SEOBNRv1/v2 FD reduced order models (ROMs) (updated)

This patch adds a total of four frequency domain reduced order models
(ROMs) of spin-aligned EOB TD waveforms:
SEOBNRv1 single-spin
SEOBNRv1 double-spin
SEOBNRv2 single-spin
SEOBNRv2 double-spin
Due to high storage requirements the binary data files are not provided
in the LALSuite git repo, but are available separately at
https://dcc.ligo.org/T1400701-v1. Put the untared data into a location
in your LAL_DATA_PATH.

See CQG 31 195010, 2014, arXiv:1402.4146 for details on how these models
were produced.

The respective source files provide more information over which
parameter space range (mass-ratio, aligned spins) and total mass
(starting frequency) these ROMs can be used. The "single-spin" ROMs were
produced from SEOBNR waveforms with chi1=chi2. I intend to develop the
SEOBNRv2 ROMs further, so consider the current ROMs preliminary.

This patch also fixes an earlier issue where the spins were not swapped
when the masses were exchanged.

This patch now calls the 'load ROM data' helper functions from inside
the waveform generators to make calling the generator directly less
error-prone.