Adds see_emote(), other cool things.

A new proc, called see_emote(), was made, to fix a few emote-related issues.  It functions similarly to hear_talk().
Features include,
- [x] Holopads can send and receive emotes to and from the AI.
- [x] pAIs not hearing emotes is fixed.
- [x] Fix carded AIs
- [x] Fix mechs
- [x] Resolve conflicts

Issues:
Populating seeing_obj may be resource intensive.  Let me know if there's a better way of doing it.
Visual emotes were changed to use get_turf().  This fixes container-related issues, but it may cause a minor issue involving people with xray not seeing emotes.  I believe breaking this is better then a snowflake check for mechs.