Tidying up Manchester OWL Syntax parser code
Moved unit tests for OWLDataFactoryImpl closer to it
Made ParserException to extend OWLParserException, and
OWLParserException a runtime exception.

This simplifies parser code as there is less need of declaring 
exceptions all exceptions thrown by a parser are caught anyway in the
parser factory to create UnparsableOntologyException, so the
checked exceptions never bubble to the surface anyway.
Manchester OWL syntax cleanup
Fixes SF 101 Manchester OWL Syntax Parser doesn't do precedence
correctly

a and b or c was parsed as a and (b or c)
This was caused by the parsing done as
parseIntersection -> parseUnion -> parseNonNaryClassExpression
which basically assigns precedence to 'or'
Reversing the calls fixes the issue.
Fixes SF 313 Man Syntax Parser gives facets unexpected datatype

No context was passed in to literal parsing. In order for 
decimal[<1.0] to be parsed as facet(min, 1.0^^decimal), decimal needs 
to be pushed to literal parsing level.