Updated all the Resolver objects to take a ModelGeneratorContext instead of the fields from
the context. Code is smaller, and was needed by distrib as it needs access to the Random
object in the context.

Added distrib test file.

Stubbed out DistribFunctionResolver, correctly identifies distrib functions now.
add first distribution function, basic support for uniform distrib
copy Random to new models, fix bug in gcc std::uniform_random, fix bug in getting default seed
add testing file
add copy ctor to random to get system time, add test for microseconds
tweak tester for Windows