Remove tintin images

Conflicts:
	client/src/models/report.coffee
Make a start on visualisation filters
Add calculateIndicatorDataBounds function to Indicator
Make indicator/:id/data route return bounds and results
Update client to expect visualisation data to be nested in results
Integer filter shows upper and lower bounds
Refactor tests to use new visualisation factory with correct data format
Merge branch 'master' of github.com:unepwcmc/NRT
Merge branch 'master' into visualisation-data-filtering

Conflicts:
	client/test/src/map_view.coffee
Refactor getIndicatorData to take a callback
Refactor getIndicatorData again, using callbacks as causes memory leaks
Clean up failing tests
Add retina image mixin
Re-add visualisation view tests
Actually test for presence of variable, not just that it's true
MAKE ASSIGNMENT UN-WRONG
Merge pull request #66 from unepwcmc/visualisation-data-filtering

Visualisation data filtering