WIP: report number of function evaluations
Revert "WIP: report number of function evaluations"

This reverts commit 8310e39bb938a47eb2ee1dd4f40fdb7d07e9bc66.
Use fixed-order Gaussian quadrature for distance in toa_phoa_snr
Add macros for branch prediction hints
Add branch prediction hints to Python wrapper
Correction: error handler is always reentrant
Whitespace
Revert "Suppress underflow errors"

This reverts commit b9f4a09762e45c107a2dd2ef7c044f5bbe733496.
Move radial integral into separate function, and add some special cases
Refactor exponential integral, add unit test
Oops, forgot to divide by two