Add a new module "disk" that takes an optional parameter (the path) and
displays free & total disk space, along with the usage percentage.
Also, added Tunnel/VPN support to the themeing of the "net" module.
First, cache lookups were bugged... Second, the output needs to call
data() first, everything else later.
This is a bit nasty, and I'll consider re-visiting this, but right now,
I don't see any other way, given that modules can now be iterated.
Add a module that displays the status of all NICs (interface name, list
of IPs and state).
In its status, it also exposes whether it's a WiFi or a wired NIC.
For this functionality, additional code was implemented to allow a
module to add multiple elements to the bar at once. The framework calls
the module until its "next()" method return False.
