ExpressionTransformer #1198: support metamodel refs to class parameters
Test for #1198: metamodel refs to shared parameters
metamodel tests #1126: updated for latest metamodel API
Fix for #2101: erasure of Callable not handled

Sometimes our Callable may be erased and we need to unerase them before calling $call
Test for #1201: Callable erasure
Test for #1201: callable erasure
Test for #1199: NPE in metamodel
Fix for #1205: direct invocation of metamodel literals

Renamed transformPrimary to transformTermForInvocation to better reflect what it is used for,
and make it handle random Terms as if they were Callable expressions
Fix for #1206: Invocations of FunctionalParameter

Make our invocation code work on Term so it can handle FunctionalParameter expressions
Test for #1205: metamodel literals invocation
Test for #1206: functional parameter invocation
Fix for #1207: indirect invocations will want callables for their LHS
Reverted fix for #1029 to fix #1207: we now unwrap invocation expressions
Test for #1207
Updated tests now that we unwrap invocation expresions
cosmetic: removed useless imports in tests
Added test for #1203
Added copyleft statements to tests (don't forget them people!)