Moved some tests from EvaluationTests into OperatorTests.
Fleshed out OperatorTests to verify type promotions for mixed type operands.

starting to sort out like/matches.  Matches is the java regex related one.  Like is the SQL related one.  But the spring .net 'like' doesn't seem to be the same as the SQL doc I found for like...

TODO moved out to readme.txt which contains latest interesting issues - they should become JIRAs when the dust has settled

added support for getValue(state,desiredType) so other nodes can ask for a transform to be done on the result if necessary, rather than duplicating conversion logic all over