added EntityContext.update
pep8
fixed matching (the "global" context must be an EvaluationContext now, not a dict)
Choice inherits from NumpyRandom
added comment/fix typo
added comments
unused import
invalidate the cache for the whole entity on new/remove
removed the commented "optimized matching" code

What Alexis has done is better anyway.
workaround to make matching work with the cache enabled
use string version of argspec
allow argspec() to received kwonlyargs both in the string and as kwargs
added (explicit) test for uniform()
added most of the random generators provided by numpy
added test for some other random generators

(randomly chosen ;-) in the list of supported generators)