v2.1.0

 - compute true vacancy using position factorization
 - add API for retrieving various quantities and rates
 - make the broker entirely reproducible from its publicly exposed state
 - use standard masks for seed in generate-score-table
 - rename 4-mer supplementary model to Wee et al. 2012
 - use a struct for representing an interaction score
 - use CBLAS (or MKL CBLAS) in odeint
 - add support for PARDISO solver