Carles/ng restructure

This is a superset of https://github.com/pretenders/ployst/pull/66

It includes a major overhaul of the angular project structure, more in line with some best practices (e.g. [Google's](https://docs.google.com/a/gagnavarslan.is/document/d/1XXMvReO8-Awi1EZXAXS4PzDzdNvV6pGcuaF4Q9821Es/edit)). This will make the project more maintainable as it grows. It is only a first step, I haven't split things out like controllers and directives etc.

I've made it a separate PR because this is more unreadable than the other one. Feel free to close #66 if you prefer to merge this one directly.