Correcting variable typo when setting distribution specific defaults of the backports mirror for the binary image.

Updating derivatives archive-key signature validiation to look by default at both debian and debian-maintainers keyrings.

Using dpkg-divert in chroot_upstart script to handle upgrades of upstart during the build (Closes: #702537).

Correcting typo directory when dereferencing syslinux symlinks when building chrooted, thanks to Luigi Capriotti <l.capriotti@xbmc.org>.

The check protecting their addition was wrong. Also fix the actual keys
with the correct architecture instead of hardcoding i386.

Removing quotes around _CGI_CONFIG_APPEND to handle multiple parameters correctly on l-b-cgi frontend.

Harmonize handling of pre-existing gnupg dotfiles in chroot when handling fake signing keys for local repository.