Remove unused import

Change-Id: I65e8c282f3bbb81cf66ee7340dc250beab4e33ff
When parsing of a message fails at either end client/server instead of assert, we
enqueue an EvStop which results in connection negotiation restart at client end
and connection deletion at the server end. Additionally
1) WriteDoc() pugi librabry api results in adding formated output i.e new-line
   characters which is useful while displaying traces. Both <iq and <message
   modified to use WriteDoc()
2) WriteRawDoc() is used during initial stream negotiation. The additional
   new-line character that WriteDoc() inserts enqueues a keepalive message. This
   is ok during <iq and <message exchange but not initial stream
   negotiation as there might be potential unintentional change of state.
3) Added check for ensuring stream open is only at the beginning of a message
   for both open and open response xmpp messages.
4) Added xmpp_stream_message_client and xmpp_stream_message_server tests to
   ensures connections are reset/deleted if the open message is not as expected.
5) Usage of XmppInit class in test-code for increasing code coverage
Code diffs to be pushed
Unwanted new line
Replace Program with UnitTest to enable memory checks
Make default parameters more useful
Install opserver and sandesh_common as regular packages and not as pip package. pip packages would be updated only if there is a change in the version. Therefore, opserver package doesn't get updated in venv even if any change is made in opserver
Add reconnect/restart logic again in discovery. Avoid recursion
Fix scons . failure in discovery client
Set the correct variable for vn_fq_name
PR:2693 Support new type ipv4 in sandesh messages
Add .gitreview to controller repository
Add copyright, etc.
Revert plugin thinning changes.
Restore https://github.com/Juniper/contrail-controller/pull/712
CI test change

Change-Id: I10acd430fd504c726aed756f230d5f08dd8a2f1d
Update README

Change-Id: Ide9ba06e20b38515994ac996d5c3acb63a8531d3