Fix post tools

Fixes

https://git.ligo.org/pe/lalinference-review/issues/14 https://git.ligo.org/pe/lalinference-review/issues/15

Notice that https://git.ligo.org/pe/lalinference-review/issues/14 still requires @john-veitch's input on what to do when margphi is used.

We can proceed anyways with this patch and fix that later on since in case marphi is present the postproc code will quietly fail inside a try..except statement, w/o killing the postproc run Also, that bit of code only calculates theta1,2,phi1,2, beta and iota, which we don't really use much anyways.