fix(events): fixed handling of onAppEvents when used from rootScope, must supply localscope, can now be used in isolate scope scenarios

Added maxSeries option for groupByNode Graphite function

fix duplicate tag value suggestions and relax limit on /api/search/lookup

feat(timepicker): lots of big changes, moving to datemath from kbn.parseDateMath, moving to moment dates instead of native javascript dates

Default limit is 25 which is too small. Considering currently the
/api/search/lookup query isn't narrowed down by selected tag
keys and values (see https://github.com/grafana/grafana/pull/1433), 
the limit is set to 3000, this should be fine because people rarely
create new graph panel.

Fixed 404 error for robots.txt