Install all packages after refresh_apt

i did a feature branch "install_packages_after_refresh_apt", which tries this.

• i needed to disable ::apt::unattended_upgrades, see "Deploy /etc/apt/preferences before refresh_apt fails with apt::unattended_upgrades":https://labs.riseup.net/code/issues/4402 bug on shared-modules
• this will fix the couchdb issue #2949 (closed)
• if (only) site.pp is applied, the leap-keyring package is installed without errors
• leap-keyring will still give an error when setup.pp is applied, but because it is installed right with setup.pp, the problem resides in our setup.pp (#2948 (closed))

(from redmine: created on 2013-06-23, closed on 2013-06-25, relates #2949 (closed), relates #2948 (closed), relates #2988)