restructure folder model to match book

- changing title of content changes it on the content (no override
titles)
- changing title marks folder as dirty
Merge branch 'master' into atc-restructure-folder

Conflicts:
	scripts/gh-book/toc-pointer-node.coffee
	scripts/models/content/book.coffee
Merge pull request #94 from oerpub/atc-restructure-folder

Atc restructure folder code (Should not affect gh-book; depends on PRs)