Merge pull request #222 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/cast_pipelines1 to master

* commit '7623c9f7':
  Few fixes in attr, choose, and debug functions
  Debug functions: remove unnecessary fallback
  Gc converted to cast pipelines, small fixes in CallHierarchyNode and Formals
  Exists: converted to cast pipeline + small fix in DimNames
  Debug functions converted to cast pipelines
  Choose: converted to cast pipelines
  CharMatch converted to cast pipelines
  Call: converted to cast pipelines
  Attr: cast pipelines + exact argument
  attach/detach cast pipelines + few tests
  Aperm: cast pipeline + specialization with dimnames