bug 985470
bug 985646
The fixes enable the OVS and linuxbridge agenets to "keep alive" when the host running the server/plugin is down.
Fixes after comments. Better logging
Fixes after comments - added reconnect interval + cleanup
Fixes after comments - simplify code + ovs intervals moved to configuration file
Fixes after comments - move int conversion to configuration
Fixes after comments - if one of the polling interval or reconnect interval are not
defined in the relevant ini files then a default value is used.
Fixes after comments and merges with HACKING.rst fixes
Fixes after port binding comments
Fixes after comments from gongysh
Fixes after comments - align comments in agent ini files
Fixes - revert some code
Change-Id: I9194f142478b130e8ef198b019539357a9916d7f
c3e7d4a7c0