Bump 0.5.3 version

Change-Id: I00a2c5cc093b025240b23ab0907ec65d5083a100
Reviewed-on: http://review.couchbase.org/26759
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>