Implement the claiming algorithm when the bot is disabled
Implement the claiming algorithm when the bot is disabled

All major use cases work as a charm (including stealing!); hashing algorithm
needs thought (currently just does concat), and need to check that all expected
events are in the right form for the algorithm.

matrix-org/matrix-appservice-irc,matrix-org/matrix-appservice-irc,matrix-org/matrix-appservice-irc