record BindingReaction state changes in a sequence in order not to loose rapid state changes
Add random_seed function to Tyche, makes it possible to re-seed the random number generator. Also expose random_seed in python.
Change BindingReaction to use large-dt scheme. At the moment the P_lambda calculation assumes a reflective boundary beneath the binding site, i.e. it takes only a half-sphere binding region into account.
Allow one to specify the number of binding sites on a BindingReaction.
Add possibility to switch an operator on or off.
Add a callback function to the BindingReaction operator, to be called when the state changes.
Merge pull request #3 from ulido/master

Some changes to BindingReaction, Operator activate switch, BindingReaction state change callback, and a random_seed function callable from python.