Always use our dpkg wrapper when mastering an image.

Always use our dpkg wrapper when mastering an image.

This changes install_packages to always have apt use our dpkg 
wrapper when building an image. The dpkg_no_scripts.sh has been 
modified to check if a package's maintainer scripts have been
whitelisted. If so, it will install without maintainer scripts. 
If any relevant maintainer script has not been whitelisted it 
will fall back to standard dpkg which will process the 
maintainer scripts.

This will allow us to transition to installing packages without
maintainer scripts in batches rather than all at once. Once 
everything is switched over we will have dpkg_no_scripts.sh 
throw an error if it encounters a package with maintainer 
scripts that have not been whitelisted.

Move postinst stuff from install_packages.sh to actual postinst 
scripts.

[tedbo, 2010-01-12 01:11:25]

The next step is a script that will help in filling in the whitelist.

[Bill Richardson, 2010-01-12 01:24:37]

LGTM.