Add max_buffer setting for streams, defaulting to 4mb
Add max_buffer setting for streams, defaulting to 4mb

Disconnects clients that have fallen more than max_buffer behind the stream.

cdgraff/StreamMachine,pedropapa/StreamMachine,pteich/StreamMachine,pteich/StreamMachine,SCPR/StreamMachine,DreamNetwork/StreamMachine,DreamNetwork/StreamMachine,cdgraff/StreamMachine,StreamMachine/StreamMachine,SCPR/StreamMachine,pedropapa/StreamMachine,StreamMachine/StreamMachine