Fix scan of Alternatives

EPGRefresh handles Alternatives properly about everywhere else but sorts them out right before the actual scan as they all share NAMESPACE, TSID and ONID.
Proper NAMESPACE, TSID and ONID are *inside* the bouquet an Alternative actually is, not inside its own SREF.
Merge pull request #37 from Schimmelreiter/patch-1

[EPGRefresh] Fix scan of Alternatives