Merge branch 'stable-3.4'
* stable-3.4:
Manage removal of refs
Use correct placeholders when logging in RevisionReader
Honour the fetch ref-spec in replication.config
Log the incoming git refs events for replication
Fix pull-replication after the removal of Log4J from Gerrit
Allow replication of refs that point to non-commit objects
Also fix the DeleteRefCommand and associated test to make it
compatible with Gerrit stable-3.5 and master branches.
Change-Id: I8d007c558fc7ebe8dbf1f8b390aad45117271270