Adding events to mongo storage engine

partially implements bp stacktach-integration

Change-Id: Ib73880195521a5cfec83399847c5374600ab2b0a
Changed record_events to use [{trait_name: trait_value}, ...] and added indexes for 'traits' to the event collection

Change-Id: I1d52d51d1027710e0a8ad654ec7044adb44fc71b
fixed bad vim tabbing

Change-Id: I9185ff7b8d253624393dfa17b26885ea0c836b66
added trait filtering for impl_mongo with latest rebase

Change-Id: Ice7a8594473446d3c5469eb4a6e90d31c5fb8350
little clean up

Change-Id: I92fe9679d82b41eeecc85be7e6feb0faea21fa66
back to single trait filtering until new branches drop

Change-Id: I187efdf6be7e854a11c630da05a0193086286995
Merge pull request #5 from TMaddox/mongo_storage_changes

Mongo storage changes