Synced rpc and gettextutils modules from oslo-incubator

The main reason for sync is to get the following oslo-rpc fixes in Neutron:
* I537015f452eb770acba41fdedfe221628f52a920 (reduces delays when reconnecting
  to Qpid in HA deployments)
* Ia148baa6e1ec632789ac3621c85173c2c16f3918 (fixed HA failover, Qpid part)
* I67923cb024bbd143edc8edccf35b9b400df31eb3 (fixed HA failover, RabbitMQ part)

Latest oslo-incubator commit at the moment of sync:
* 2eab986ef3c43f8d1e25065e3cbc1307860c25c7

Change-Id: I2f5bb0d195e050f755ecdbf06a6bbed587a04fbe
Closes-Bug: 1281148
Closes-Bug: 1261631
Merge "Synced rpc and gettextutils modules from oslo-incubator"