Merge pull request #87 in G/fastr from ~MICK.JORDAN_ORACLE.COM/fastr:feature/addmatrix to master

* commit '24c79f20':
  Add TruffleBoundary to identical(RFunction,...) slow path
  Handle builtins in identical(RFunction)
  reinstate code that used to be in RRuntimeASTAccess.callback for case when no frame (e.g parser errors)
  remove debugging code
  Fix identical(Function) when not trivially the same function - fixes warning on Matrix package load
  Avoid assertion on RCaller
  Add RCaller argument to Engine.evalFunction
  Fix more RCaller.invalid calls
  Fix RCaller.invalid
  fix RCaller regression in HiddenInternalFunctions
  Update ExpectedTestOutput
  copyright fix
  test all recommended packages