Added disk filtering

Updated the Rocket.toml example

Rocket.toml.example

@@ -2,3 +2,5 @@
 template_dir = "templates"
 address = "0.0.0.0"
 network_interface = [ "eth0", "eth1" ]
+mount_names = [] # All disks and mount points
+json_rpc_url = "http://127.0.0.1:18081/json_rpc"