Resolve "Allow use of TEMPO2 barycentring time delays accessed via libstempo"
Resolve #38 (closed).
This PR allows the heterodyne stage to use TEMPO2 for calculating the phase evolution - this can only be used if performing the heterodyne as a single stage. Just as a note for future reference, when calculating the phase with libstempo we cannot directly use the phase()
method - this is because internally in TEMPO2 the phase does not get calculated using the reference epoch; instead phaseresiduals()
, which does get calculated with the reference epoch must be used, and the phase number must be added.