Allow apps in feed collections to be grouped
Merge pull request #2194 from chuckharmston/grouped_collections

Allow apps in feed collections to be grouped.
Fix migration conflict
removing unneeded .mozilla.com
Merge pull request #2200 from andymckay/less-hosts

removing unneeded .mozilla.com
feedapp/feedbrand/feedcoll search for transonic
BaseIndexer class, factor out webapp indexer code
refactor reindex_mkt to run on arbitrary indexes, notably for feed elements
remove amo reindex flagging stuff
get reindex_mkt fully working
fix tests / address review
maintain feed indexes through post_save
get feed search view working