Multithreaded FloatingPointExceptions Service

Modify the EnableFloatingPointExceptions service to
work with the multithreaded framework. Modify it to
use the new service interface. It now uses the Framework
to keep track of the stack of modules which are currently
running instead of an internal stack.  It does this through
the ModuleCallingContext. Modify the beginStream and
endStream service callbacks to take a ModuleCallingContext
argument. Modify the MessageLogger and Tracer to reflect
that interface change.