stackdriver: broadcasting through $scope doesnt work anymore since query_filter_ctrl is now a sibling directive to query_aggregation_ctrl, so broadcasting is now done using $rootScope

stackdriver: WIP - implement stackdriver style auto alignment period. also return the used alignment period and display it in the query editor

filter NULL values in column value suggestion query

alerting: move all notification conditions to defaultShouldNotify

stackdriver: make sure service and metric display name is used instead of value when loading a saved query editor