Documented detailschange/formechange and other minor changes

Added detailschange and -formechange, which detail when a pokemon
undergoes a forme change (Mega Evolution, etc.), as well as -transform,
for when a Pokemon uses Transform/Imposter.

Added damage-related messages: -crit, -supereffective, -resisted, -immune.

Added details regarding items via -item, -enditem.

Added more detail about status messages with -curestatus, -cureteam.