Enhance the debian build rules so it will create multiarch compliant
packages on those distributions that have support for it.
Also remove e2initrd-helper from the e2fsprogs package since no one
uses it any more.
Also update the debian policy standards version to 3.9.2.
Addresses-Debian-Bug: #632169
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>