Migrate Generators to New Random Service Interface

Migrate generators to use the new interface of the
random number generator service designed to work
with the multithreaded Framework. The main interface
change is to require a StreamID or LuminosityBlockIndex
argument to the getEngine function. In most cases,
this required moving code from the constructor to
the event or beginLuminosityBlock method. Then a pointer
to the engine was percolated or passed in some way
to the point where it was used.

In some cases, I added declarations of shared resources
where it was obvious they were needed, but I did not
thoroughly check for and declare all shared resources
that will eventually be needed.