install-chef-suse: Make script idempotent wrt /etc/resolv.conf

Since crowbar overwrites /etc/resolv.conf, we need to keep a copy of it
on the first run of the script to be able to get the original data on
later runs.
install-chef-suse: Move commands around

Perform some cleanup and creation of json files a bit later on, as this
is clearly not needed yet when installing barclamps.
install-chef-suse: Install crowbar barclamp like the other barclamps

It's the exact same command, so just use the same code path.
install-chef-suse: Remove duplicate check for running in screen
install-chef-suse: Move line around, where it makes more sense
install-chef-suse: Add a summary line when installation is complete

This is just nicer in the output.
Merge pull request #1879 from vuntz/install-chef-suse

install-chef-suse: Some cleanup + fix re-running the script wrt /etc/resolv.conf