Synced log module and its dependencies from olso-incubator

Old version of 'log' module depended on oslo-incubator RPC layer
implementation. This sync is intended to copy the following fix that
makes log module use oslo.messaging.notify.log_handler if available:

  * 109e325e: Use oslo.messaging to publish log errors

blueprint oslo-messaging

Change-Id: Ieb26df4e9fbb2aa4d319c79be7510006fc8461ab
Merge "Synced log module and its dependencies from olso-incubator"