Disable the tests that time seed gives different answers from specific seed for Poisson (same problem as we had with BinomDist, but less common).
trim history somewhat, and make it and README consistently 80 char width rather than 100 we use for code.
added port files needed for those who want to install using Macports
put correct MacPorts installation instructions in INSTALL.md
Merge branch 'master' into #248
more details on finite grid effects, and noise effects
(#248)