Removing deleted extensions. Fixes #4.

I simplified the extension management. We reload _all_ the extensions when a FS
event is detected now. It would be nice to do that on a per-extensions basis,
but, alas, it complicates matters too much.
Do not fail when extension is being built.
Changed routes to end with extension name.

This is a workaround for Kitt that doesn't handle proper REST URLs yet.
Merge pull request #6 from kitt-browser/fix/change-routes

Fix/change routes