[Review] Request from 'schubi2' @ 'yast/yast-network/review_141001_autoyast_do_not_overwrite_firewall_settings'

Please review the following changes:
  * efc4dc8 typo
  * 0f78165 added testcase
  * 1b545dd Revert "adapt Rakefile to submit to correct build service project in maintenance branch SLE-12-GA"
  * 0e4e651 adapt Rakefile to submit to correct build service project in maintenance branch SLE-12-GA
  * a56e86a removed not needed import
  * f8bc950 moved autoyast stuff into lan_auto.rb
  * 03880f6 packaging
  * c441ccf Autoyast: Do not overwrite in autoinst.xml file configured firewall settings by installed firewall settings if the installed network is kept.

Test-specific helpers should be encapsulated in `require_relative "test_helper"`