Improved chart registry and view classes.

- Service:Overview Removed Chart Registry offset handler.

- Controller:Home Removed Registry updater.

- Controller:Overview/Related Added new method for chart identification.

- Controller:Overview/Correlated Added new method for chart identification.
Correlations Chart dimensions with xScale domain map.
Added functions and models of tables for dealing with political events sourced from news articles
debug correlated charts.
Merge branch 'feature/visualisations' into feature/angular
More work on the political overview methods - should now return department activity list relating to last 30 days
Added methods for events and regions to political overview
fix tablestocharts not finding table origin id
Text changes on Home page. Correlation error handler.
Merge branch 'feature/visualisations' into feature/angular
Removed political overview whilst fixing tests
cut down urls test to 1 so as not to waste embedly calls
Merge branch 'feature/visualisations' into feature/angular
Handle userid internally for api calls, remove need for discoveredby parameter in calls by searching internally to see if table has been discovered
Overview grid fixes.
Merge branch 'feature/visualisations' into feature/angular
fixed obs api
Route fixes with chart key. Save observation API mockup.
Merge branch 'feature/visualisations' into feature/angular
fix obs pt2