Add objectByName() and ensureObject() utility methods, ViewCollection's views to define subtypes by name
Removed unnecessary line from ViewCollection.prototype.typeFromModel()
ensureObject -> maybeByName
Merge branch 'develop-frontend' into feature/issue-367-viewcollection-should-allow-view-subtypes-to-be-defined-in-a-way-that-solves-circular-dependency-problems

Conflicts:
	go/base/static/js/src/components/structures.js
	go/base/static/js/test/runner.html
Merge branch 'develop-frontend' of github.com:praekelt/vumi-go into develop-frontend