Update README with MidoNet compatiblity

Add MidoNet version compatiblity information to READ file.

Signed-off-by: Ryu Ishimoto <ryu@midokura.com>
Add debian directory

Add debian directory from Ubuntu Cloud Archive's grizzly package.
This build packages intended for Precise.

Signed-off-by: Ryu Ishimoto <ryu@midokura.com>