[MESSAGE BUFFERS] Initial checkin of feature.
Created MessageBuffer class.
Changed all references to ConnectionInstance::send to pass MessagePtr values.
Rough conversion of all calls to ConnectionInstance::send, obvious optimizations possible.
Changed write callback to use new sending method.
Merge branch 'messagebuffers'
Issue #1: Don't duplicate message buffers.
Feature works, no known memory leaks in initial testing.
Optimizations possible.