this will allows us to just do apt-get install aegir to upgrade all three packages

this also disables (chmod 0) the manual drush_make install so that
drush doesn't freak out on the duplicate code copy.

Refs #1309080.

this will make sure things fail properly, see #1300216

the rationale here is that it's then easier to install aegir for a client or somebody else than you

somehow we get prompted for the mysql password twice

this is a test commit, but apparently the way things are right now,
those things are never prompted even though aegir/site is high
priority.

 * upload to unstable
 * fix commitlog to indicate the jenkins build tag
 * make PGP key customizable

This reverts commit 9396b6b2.

That's beacuse it may be preseeded, and anyways it's already cleared
in postinst