* gotcl.go: Frame variables are pointers so they can be linked via
  upvar.  Interp.Eval calls new Frame.Eval so you can call into a
  frame's space via uplevel.
* gotcl.go: Frame variables are pointers so they can be linked via
  upvar.  Interp.Eval calls new Frame.Eval so you can call into a
  frame's space via uplevel.