New proposal modal - Please do not merge (see below)

On my way to trying to complete the [Modal Add Proposal Screen task](https://trello.com/c/JTUJXuU6) I've been trying to learn all the new pieces, Backbone etc. I'd like to propose anyone interested in learning about (or teaching) this new architecture to look over the attached code and for us to learn and accomplish by completing and making it work tomorrow night.