Add CHANNEL_GROUPS_SUMMARY annotation

This outputs the ID and aliases of each channel group a
channel is part of.
Merge pull request #204 from atlasapi/channel-summary

Add CHANNEL_GROUPS_SUMMARY annotation
Merge pull request #205 from atlasapi/broadcast-location-attributes

Add model attributes on location and broadcast
Correct JAXB tags
Merge branch 'master' into stage