Proper use of kore_strtonum64().
Add websocket support to Kore.

Introduces a few new api functions:

- kore_websocket_handshake(struct http_request *):
	Performs the handshake on an HTTP request (coming from page handler)

- kore_websocket_send(struct connection *, u_int8_t, void *, size_t):
	Sends data to a websocket connection.

- kore_websocket_broadcast(struct connection *, u_int8_t, void *, size_t, int):
	Broadcast the given websocket op and data to all connected
	websocket clients on the worker. Note that as of right now
	the WEBSOCKET_BROADCAST_GLOBAL scope option does not work
	yet and messages broadcasted will be restricted to workers
	only.

- kore_worker_websocket_broadcast(struct connection *, void *, void *):
	Backend function used by kore_websocket_broadcast().
	Could prove useful for developers to have access to.

A simple example is given under examples/websocket.

Known issues:
	Kore does not support PING or CONT frames just yet.
Remove lingering diff file