Fixes #1006
Fixes #1006

- ensures an array is always passed to `Collection#parse`
- clarifies documentation for `Collection#set`, `Collection#add`, and `Collection#reset`

jordansexton/bookshelf,bookshelf/bookshelf,rbong/bookshelf,bookshelf/bookshelf,jadengore/bookshelf,jadengore/bookshelf,seegno-forks/bookshelf,jordansexton/bookshelf,TinOo512/bookshelf,apla/bookshelf,seegno-forks/bookshelf,rbong/bookshelf,tgriesser/bookshelf,tgriesser/bookshelf,chrisbroome/bookshelf,TinOo512/bookshelf,jadengore/bookshelf,apla/bookshelf,chrisbroome/bookshelf