o.c.archive.reader.sdds: The prefix for the extension is now sdds://.
With xnds:// the SDDS archive reader gets the URL of the channel
archiver, depending on the order of the InfoRequest.
Merge branch 'develop' into rel15x

Conflicts:
	applications/plugins/org.csstudio.archive.reader.sdds/plugin.xml
	applications/plugins/org.csstudio.archive.reader.sdds/src/org/csstudio/archive/reader/sdds/SddsArchiveReader.java