Now that I'm done doing the "yay! it works!" dance, it's time to commit!

Base the project model on QStandardItemModel and QStandardItem. This provides us a cleaner model implementation since we can use the APIs provided by Qt rather than using an abstract model and making up our own APIs.

The generic file manager is the only one that is correct in terms of display, and I have tons of bugs to fix, but this is a good first stopping point since i need to merge with trunk again.