Context reimplementation by high-level means of xreate
Syntax/Interpretation:
`query_scope` intrinsic multiple fixes, debug functionality, expressions tagged as 'bpoint' raise SIGINT for debugger
Intepretation:
Operator::Variant fixed functions resolution fixed
Compilation:
removed low-level context functionality(compilation/latecontextcompiler2.cpp), scope overrides fixes
AST: guard used from now on rather than guardContext
Tests: Virtualization.test2, Association.QueryScope1, Interpretation.PartialIntr_4, Interpretation.Variant1