Convert generic StringParameterValues to Project Defined Types

Applying Default parameters was refactored so it could be handled in the
same manner as converting the value types
tests for default parameter values
test coverage for project specific parameters
eliminate unneeded abstraction
Reverted unnecessary changes in #62.
Merge pull request #62 from zeroem/job-specific-parameter-passing

Attempt to Convert StringParameterValues to the type defined in the project