For TCL extension:

For TCL extension:
  Cleanup TCL library interaction and interpreter management.
  Group code into more purpose oriented functions.
  Add .unknown dot command, delegating to TCL commands with "dot" names.
  Drop planned .eval new dot command.
For shell:
  Implement undocumented .unknown dot command, doing little.
  Make dispatcher call .unknown's implementation for unknown dot command.
  Fix a command lookup bug exposed by above change to unknown handling.
  Add .eval dot command.
  Add options to .x command aimed at control of errors in command sequences. (a WIP)
  Make dispatcher report ambiguous dot command lookups, even with no extension.

FossilOrigin-Name: 7616a6f4abe20699e5aa66018233247aa94e3e87f3e6ebe1357f776a18115eb3