Disentangle Console Objects

[dthain]

The console module has several ideas all tangled together:

• A console object that sits on top of a graphics object to provide text for any window.
• A device abstraction on top of any console that allows it to be read/written like a device.
• A singleton abstraction representing the master console for the system, created at startup.

These abstractions need to be pulled apart and clearly distinguished (perhaps renamed) so that other parts of the kernel invoke them properly. In particular, the master console for the system may be better represented as a kobject, so that console messages can be sent to different places, as needed.