NOT WORKING

added OWL and RIF translators (still called compilers) to their own compiler packages
Modified RIF parser to properly parse RIF-core (Frame and Atom args must be "base terms" rather than terms, which means any term but list)

as Externals can be base terms, these have been moved to be Datums.

Also added a catchall RIFConst, RIFUnrecognisedConst, which has a variable RDFDatatype.
added a clone() method to CompiledProductionSystems to allow forking as an alternative to partial subsystems
Added a SourceRulesetPair to hand to the RIF compiler
Created a ContextConsequence function for providing bindings instead of triples.

Added an alternative constructor to TripleConsequence function to allow for source rule sets not constructed in the Jena Rule format.