Merge branch 'grc' from http://gnuradio.org/git/jblum.git into master

Merge branch 'grc' from gnuradio.org/git/jblum.git into master

  we dont use test() -> remove it
  Made the window for the pass band filters integers (take firdes.WIN_XXX).
  Evaluation fix in param.to_code().
  Removed the flagging api and usage from the base classes.
  added ref scale param to fft and waterfall
  Switched the python classes to inherit from the base and gui classes.
  port and param types from an overloaded method
  todo
  Replaced TYPES in Port and Param with types parameter.
  made is_virtual_xxx a block level function, used by port and param classes
  added stream id type and checking in evaluate
  avoid loops
  Recursive resolution of virtual sources.
  added virtual source and added stream ids, logic to clone in port
  added rewrite methods to element to separate from validation logic
  Added virtual sink and logic to clone port.
  removed repurposing of pads
  Work on command line options for generated code.
  renamed the colors dialog to types
  use pkgpythondir
  ...