run-after-edit-sequence

• (send a-mred:media-edit run-after-edit-sequence thunk tag) -> void
      thunk : a procedure of no arguments
      tag = #f : symbol or #f

  The procedure thunk will be called immediately if the edit is not in an edit-sequence. If the edit is in an edit-sequence, it will be called when the edit-sequence completes.

  If tag is a symbol, the thunk is keyed on that symbol, and only one thunk per symbol will be called after the edit-sequence. Specifically, the last call to run-after-edit-sequence's argument will be called.