FR/objective list: Enhanced scripting development experince

It'd be really nice if there were a means to do scripting development without restarting the game for every change, and the blingblong of error message popups haunts my nightmares. There are a number of things that I think taken all together would enable some tantalizing workflow possibilities, so I'm making one issue right now instead of shotgunning a bunch of small ones into the tracker.

- [ ] lua eval/ REPL on debug console, with automatic session logging
- [ ] Debug console in detached window, usable with or without game paused.
- [x] Lua errors and warnings written to log without popup or pause.
- [x] Lua `error()` calls being non-fatal events.
- [ ] API functions to check current hooks and remove existing hooks

If all that were in place I think effective REPL style development would be in reach with a bit of supporting script design.