Updated the README.Debian

- It referenced quemu-kvm, which will no longer exists after wheezy. This
  now has been replaced with simply qemu. Additionally sgabios not only works
  in qemu-kvm, but in any qemu as long as SeaBios and X86 based hardware is
  emulated.
- The examples mentioned the command kvm, which is deprecated after
  wheezy. The examples have therefore been corrected (and a bit reformated).
- Removed the mentioning of version 1.1 of qemu. There is absolutely
  nothing special with that specific version in regards to sgabios. Addtionally
  we can safely assume that a recent enough qemu is present on the (Debian)
  system, since otherwise sgabios would not be installable...
- Added a hint which package needs to be installed Debian to get the X86
  hardware emulating qemu
- Some additional minor corrections and reformatting
Added /mjt to the uploaders