removed all references to signPostHelper

This should prevent rate overflows for good
mark/display timeseries-obtained fitbit data as 'allDay'

also, have all-day items show up in a separate, top section in the list view, and don't show them in the clock view
Don't display empty sleep facets on history import

and added a generic mechanism to mark certain facets as 'empty' - can probably be reused for the Bodymedia connector
adding support for food and user entry notifications
WIP: adding food logging support
fixed apiSubscriptions call to use POST, added water history import
added a simple test to reproduce the fitbit subscription 401 issue
set the test back to reproduce the issue
WIP: fixed apiSubscription issue, facet extraction mechanism, and more...
Merge branch 'development' into feature/fitbit-improvements

Conflicts:
	fluxtream-connectors/src/main/java/org/fluxtream/connectors/fitbit/FitBitTSUpdater.java
Merge branch 'development' into feature/fitbit-improvements
WIP: aggressive log updates improvements

more avoidance of rate limits, keep spare calls for incremental updates
oops, wrong direction
WIP: Fitbit food logging improvements

Added VOs & templates (placeholders only for now)
fixed food log entries persistence
WIP: Fitbit food logging, fleshing out the frontend templates

also:
added a generic way for facets vos that are potentially all-day to tell if a particular instance is all-day
added an optional order by clause on an objectType basis (so that log entries can be sorted by meal type)
added more null checks to FitbitTrackerActivityFacetVO
WIP: Fitbit food logging improvements

- fixed facet extraction using createOrUpdate for food log entries
- better templates
- improved Rate Limit management
- improved incremental agressive backfilling
WIP: Fitbit food logging improvements

get the ordering of food log entry facets right
fixed missing null check for intraday data
removed dead code
added an aggressive "backSynching" mechanism

to compensate for fitbit's lack of 'updatedSince' semantics