Maximum frequency

Closes #104

This MR changes the indices used in various for loops so that only the frequencies in the analysis band are used when doing things like calculating templates and residuals.

I'm fairly sure this shouldn't actually change any results, the option to specify an fhigh is already present and used at various places, e.g., inside the likelihood integral, in the BayesLine model, and I think in the frequency prior for wavelets.

This MR does speed things up a decent amount when the sampling rate is significantly above the maximum frequency.

I'm running some tests with the igwn-py37 version and this version to verify that everything is still consistent, I'll update here when they finish and try to include run times.