Refactor go.apps.http_api to build on go.apps.http_api_nostream and avoid duplication.
go.api.conversation_api mucks about less in go.apps.
Merge branch 'feature/issue-811-HTTP-API-DRY' into develop
Split up MessageMetadataHelper and avoid duplicating its functionality in ConversationWrapper.
Use new MessageMetadataHelper in a few more places.
Fix url token message sensitivity.
Undo silly change.
Use a helper instead of building messages manually.
Merge branch 'feature/adhoc-mdh-improvements-from-821' into develop
Excise paging feature and have search return keys instead of objects
Merge branch 'develop' of github.com:praekelt/vumi-go into feature/issue-809-contacts-resource-search