Revamp project handling UI

The current project handling UI grew organizally from whatever happened to already be there, and people find it confusing. It should be replaced by something that acts more intuitively. Some improvements would be:

1. A tree view whose parts can be expanded and collapsed at will, instead of having only one currently expanded path.
2. Reordering and moving projects by drag and drop (with perhaps a sort button that puts the projects back in order, by time or alphabetically?).
3. A search or filter bar to look for projects based on substrings of the name.

All of this fits into the current model (with some added metadata for ordering). It's just a client-side revamp.