Fixes to effect constraint generation to properly check effect coverage
Added support for getPLTerm for RplElement classes.
Implemented getPLTerm for Rpl class and fixed bug I just introduced
in the constructor of ParameterRplElement.
Adding const qualifier to Rpl::getPLTerm()
Adding implementation for getPLTerm for Effect, Substitution, SubstitutionVector classes
Moved some implementation from the .h to the .cpp file and fixed a silly bug
Adding getPLTerm functionality directly to OwningVector and removing it from SubstitutionVector.
This is done because now it can be used by SubstitutionVector, EffectVector, RplVector,
ParameterVector, and any other classes that extend OwningVector and implement getPLTerm for
the vector elements.
Merge branch 'pl-terms-rpls-effects' into dev/prolog
Local branch 'pl-terms-rpls-effects' implements getPLTerm for
many of the classes that we need to communicate with prolog for
effect (and later full) inference.

Conflicts:
	lib/StaticAnalyzer/Checkers/ASaP/Rpl.h