Check that the IP address of the admin node is in admin range

This is a prerequisite before installing things.

https://bugzilla.novell.com/show_bug.cgi?id=774878
Set up bc-template-dns databag with correct domain and forwarders via a new Ruby script bc-dns-json.rb
Fix a few $CROWBAR_TESTING issues

- barclamp-templates and autoyast profile template might not be present in
  /opt/dell/chef/ when installing from source
- Skip checks for NCC repos when $CROWBAR_TESTING is set
- Check if repos already exist before adding them
- Updated documentation
Merge pull request #1793 from rhafer/master

Some additional pieces to bring install-chef-suse.sh back into shape