We now have DevFileSystem which is derived from RamFileSystem. All
devices are RamInodes. We don't have separate DeviceManager anymore.
To iterate over devices, you can loop througn every inode in devfs.
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.
This is a big commit that was kinda hard to split to smaller ones.
Essentially we now look at all the mass storage devices from PCI
and initialize (P)ATA devices. This doesn't provide any more functionality
but better abstractions and everything doesn't have to be on its old
default port that might be different for modern computers.