1.393 - on path to 1.4

- Added Hurricanes data
- map and map2stan no longer require start values --- they will sample
from priors if no explicit inits are given
- Added some basic error trapping to map and map2stan
- compare supports WAIC now
- map now allows vector parameters, via an abstraction layer that
translates to scalar for optim and then back again
- precis suppresses vector/matrix parameters by default; optional depth
parameter displays them
- added postcheck, which computes and plots posterior validation check
for each case in data (uses link and sim internally)