chore(docs/contribute): add note about serving the docs
feat($parse): support trailing commas in object & array literals

Per ECMAScript 5.1 specification trailing commas are allowed in object and
array literals. All modern browsers as well as IE>8 support this syntax.
This commit adds support for such syntax to Angular expressions.
Merge branch 'master' of github.com:ashleygwilliams/angular.js