* fixes handling of multivariate distributions as priors
* run_compute sample_from: use serial mode when sample_num is 1
* run_compute when passing solution instead of sample_from, default to sample_num=1 if adopt_distributions is False
* export_solver: exclude unneeded distributions/solutions from the exported script to optimize filesize
* export_solver: adds (undocumented until 2.4 release) support for autocontinue
* export_compute: do not require explicitly passing compute if only one exists matching the filter
* calculate_lnp: include_constrained now defaults to True