Add lag energy spectrum function
- Add new timing-tools function "lag_energy_spectrum"
- More verbosity behavior in "segment_lc_for_psd"
Edits to foucalc code:
- Enable use of "rate" instead of "rate1"
- Export CPD calculation into new function named cross_spectral_density
- also compute the standard error on the mean of the averaged cross-spectrum
- colacal: Add Uttley+14 error calculation to time lag calculation, return struct instead of 6 output parameters
- Clarify help in dorDTF: This DFT has a normalization of sqrt(n)