Removed sb-new-client-filter.

Instead of switching filters, a bool variable is used to determine if a
client has not yet received the buffer content of the shared buffer.
The message is split into chunks on the server-side.

This solution is a little hacky, and should be replaced.

Also added workaround for auto-fill-mode. If more minor-modes proves
disturbing, the workaround should be generalized for all problematic minor
modes.
Sends each message in a 2048 (or less) chunck.
tiny change
Added a semaphore to the client.
Sends ack after a message is received.
Removed newline.