Add Live Reload using WebSockets

[wh1le]

Adds WebSocket-based live reload support (edited, deleted, created)

What's included

• LiveReload server - uses listen gem to watch and faye-websocket to push changes
• Rack middleware intercepts WebSocket upgrade requests at/_live_reload
• Frontend JS - connects via WebSocket, fetches fresh HTML on change, swaps .main content and nav sidebar
• Config - live_reload: true by default, disable with --no-live-reload or live_reload: false in .madness.yml

[DannyBen]

Thanks. There are issues with this PR that need addressing before I can decide if I want to merge it.

1. It seems to originate from an outdated commit (62 commits behind).
2. I prefer to avoid negative flags. No --no*.
3. Live reload, if added, should be off by default.
4. Live reload should work out of the box for non evented file systems (use polling only or by default).
5. Tests should at least pass, and at most provide 100% coverage.

Even if all these are fixed, I am still not sure I want to merge - there is more overhead than I am comfortable with, but if the above is fixed, I can at least start to evaluate.