Requeu and acknowledge logic for server

- no_ack should not be used with requeu implementation at same time
rejecting message when no_ack set leads to:
PRECONDITION_FAILED - unknown delivery tag

- metadata.ack will guarantee that message is delivered and started
processing

Change-Id: I15d940f635b1d0f80ac1eaefc8f37a3080e7f4d2
Closes-Bug: 1349399
Merge "Requeu and acknowledge logic for server"