Rebuild

Wanted nested subfolders in their own groups, ended up rewriting most of the app. Oops.

Tests are good though!

```
=============================== Coverage summary ===============================
Statements   : 99.11% ( 222/224 )
Branches     : 96.58% ( 113/117 )
Functions    : 100% ( 53/53 )
Lines        : 99.11% ( 222/224 )
================================================================================
```

KNOWN BUGS
===========

* Comments aren't retained