resip/stack: ConnectionBase: WS manage mBufferPos

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10163 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/stack: ConnectionBase: WS eliminate copy

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10164 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/stack: ConnectionBase: WS eliminate c_str() usage that may result in copy, fix string termination

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10165 ddefafc4-47db-0310-ae44-fa13212b10f2