Remove jester from default role set

The inclusion of jester was causing a disproportionately high number of wolf wins due to wolves voting jester as a strategy in order to bring numbers to even. Per discussion in -ops, it was decided that removing jester would be good in order to prevent this (an alternative option being reducing number of wolves so that the gameplay can still happen, but it requires more finesse on the wolves' part in order to utilize).
!roles properly displays roles that drop out, and can show roles for a specific player count
!stats orders names in join order
fix !roles with argument
add missing period for matchmaker message in !simple
Do not display duplicate death messages, a night kill overrides any chained kills (lovers, scientists, assassins, etc.)
Allow hunter to change their kill at night using !kill without needing to !retract first
Add option for mad scientist to skip over dead players, based on how many players joined the game