Fixed defm_motif_parser reading covariate names as motif terms: a
formula such as {y0} > {y0} x Day1 silently added y1 to the motif.
Variables are now only read from the bracketed groups. Also fixed
{...}x Covar (no space before x) silently dropping the covariate,
transitions accepting current-time rows on the LHS (e.g., {y0_1} > {y1}),
and unchecked out-of-range rows with Markov order 1
(USCbiostats/barry#26).
Fixed support-vs-array index confusion in Model::sample and
DEFM::simulate, which produced wrong draws when simulating
(USCbiostats/barry#25).
Fixed catastrophic hash collisions in FreqTable::make_hash and vecHasher:
hashes of small-integer statistics had no entropy in their low bits, so
std::unordered_map placed (nearly) all keys in a single bucket, making
support computation O(4^ncol) instead of O(2^ncol). Models with many
response columns (e.g., 16) appeared to hang during initialization
(USCbiostats/barry#24).
FreqTable::add() now verifies the stored row on a hash hit and keeps
true 64-bit hash collisions in a per-hash overflow chain, so distinct
statistics can no longer be silently merged (USCbiostats/barry#24).
barry's versioning.