We don't store the error message anymore in BAN::Error.
Instead we store a error code that can be mapped into a string.
This allows BAN::Error to only take 4 bytes instead of 128.
We should also make some kernel initialization just panic instead
of returning errors since they are required for succesfull boot
anyway.
We now use Device abstraction that will allow us to provide devices
to userspace through /dev. Currently Shell reads from first and only
device (it being PS/2 Keyboard).
Bananymous