Modified process_accents to prevent the accidental saying of slurs, and log the process that would generate them

[amylizzle]

About the PR

This PR modifies the process_accents call of say() to prevent a bad stack of mutations from causing people to accidentally say slurs. We also add logging, so that when this does happen there is a record of the speech effects that caused it. Admins should now only receive message pings for intentional use of slurs.

Example:
For the purposes of the test, "tatties" is considered a slur.
The user says "I like potatoes" with no accent. Everything is fine.
The user says "I like potatoes" with the scot accent, which gets mutated into "I lik tatties" - bad word. This gets garbled into "I lik der", and logged. No admin message, just log.
The user says "tatties" - bad word. The admins get a message.

Why's this needed?

Currently a bad stack of speech mutations can cause a play to accidentally say a slur while begging for mutadone. That pings the admins, who then need to investigate the context to make sure everything's okay.
Saying slurs is bad, saying them accidentally is unfortunate.

Changelog

(u)Amylizzle
(+)It is no longer possible to accidentally say a slur due to speech mutations.