New polymorphic Lua-class implementation + tests Polymorphism: * Far less project-specific code to maintain in the Lua-class Log as the bulk of set-theory operations is in a shared base-class (Cref) * Code simplified, clarified and streamlined to be as similar as possible to Log-class sibling Trace * Functionality-redundant API's removed Tests: * Test-framework ported from utrace/lua-cref * Minor adaptions where needed only * Test-suites & tests specific project implemented (basic)