Fix an issue with the new "no print" code in the IPP backend - since we don't

Fix an issue with the new "no print" code in the IPP backend - since we don't
always read on every pass through the loop we can't use "bytes" as an indicator
of success.

Increase the size of buffers for the socket and lpd backends; 1k for socket to
avoid blocking/fragmentation on a write to the socket, and 16k for the LPD
backend since we are writing to a file.

git-svn-id: svn+ssh://src.apple.com/svn/cups/cups.org/trunk@9745 7a7537e8-13f0-0310-91df-b6672ffda945