Shorten some long lines
Match littlehope default SNR threshold to realize_coincs
Add --f-low option to bayestar_realize_coincs
Implement I0(snr^2 |autocorrelation|) likelihood
Use Gauss-Legendre quadrature over cos(inclination)
Use fixed-order Gaussian quadrature for distance in toa_phoa_snr
Add macros for branch prediction hints
Move radial integral into separate function, and add some special cases
Add unit tests for catrom()
Add unit test for cabs2
Whitespace
Add more comments to eval_acor
Rearrange functions to match order of unit tests
Comment cabs2
Add unit test for eval_acor
Fix improper summing of Gauss-Legendre points

By mistake, I had basically implemented:

    y += w[N] (f[N] + w[N-1] (f[N-1] + ... + w[1] f[1]))

instead of:

    y = w[1] f[1] + w[2] f[2] + ... + w[N] f[N]
Fine-tune time of arrival prior
Make module init function Python 3 compatible
Drop bayestar_sky_map_toa_snr
Move unit tests to main source file