use 'proposition' type main navigation
update licensing subnavigation
remove category titles, remove services page feature flag
Load override feature toggles if present

- Extract a class for loading feature toggles.
- Load an override feature toggles file if present.

This allows us to override feature toggles on a per-environment basis.

@pbadenski
@robyoung
Refactor feature toggles to be more Rails like

It seems as though application logic should not live in the config directory so FeatureFlags has moved to lib.
Keep yaml configuraton together in config dir
merge master into navigation
fix erroneous copy
Realtime visitors for FCO transactions
Enable FCO realtime visitors only on dev
Merge pull request #96 from alphagov/environment-specific-feature-toggles

Environment specific feature toggles
merge master into navigation
highlight 'services' link on fco pages
Merge pull request #97 from alphagov/navigation

Navigation
Feature tests for licensing availability data
Merge branch 'realtime-visitors-for-fco'
Should use feature toggles in a new way
bugfix - include missing controllers in rjs build
bugfix - use correct week for fco success rate
bugfix - allow 0 values in success rate view