Divide basic tests into contexts and POs.
Override Overtur's Op Context processing.
Pog prefix to visitor.
Implicit Op Context only collects frame variables.
Parse error now leads to test failure rather than stack trace dump.
Add tests for Ctxt Collection of Implicit Ops.
Sat PO now takes frames into account (although rd and wr are treated equally).
Add console and errors to pog perspective.
Rename test so it runs with maven.
Cope with more Overture renames.