* stable-5.0:
Silence API warning for new ObjectIdSerializer introduced in 4.11.1
Ignore API warnings
Fix photon target platform to use photon version of org.eclipse.osgi
Update Photon orbit repository to R20180606145124
Suppress warning for trying to delete non-empty directory
Fix fetching with duplicate ref updates
Fetch(Process): should tolerate duplicate refspecs
FetchCommandTest: test add/update/delete fetch
Change-Id: I9e7fa37b100a7ea3cbe4104802d36c6f38df9e08
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>