data argument to proto_* functions

[nspyrison]

Would be nice to have data arguments in proto functions themselves instead of the current workaround of relying on proto_highlight() and specifying rownum_index.

requirements:

• passed to any proto_DATA* (not proto_basis) and processed in .init4proto.
  -if data arg passed; used instead of data passed in ggtour(), though doesn't over back to the set_ggtour
  -must be comformable to matrix of [n*, p] else error

Probably negligible performance gains, but would feel more like ggplot2 than current rownum_index.

[nspyrison]

Caused too many issues in the proto call; wouldn't work with facet, fixed_y, etc.