Stop and restart multiple processes by pid or name

Multi stop:
`bs stop 1111 2222 3333`
Multi restart:
`bs restart 1111 2222 3333`
Stop all:
`bs stop all`
Restart all:
`bs restart all`

fixes #18 
Doesn't changing pointy brackets for square ones make the argument optional?  It'd be a shame to lose the 'missing required argument' message