transforming listings to tables in chapter networking

Also fixed the width of some columns.

Change-Id: I42422a1d63bca12d290a546af423d73c27974d8b
cleaning up several programlistings

  * removing newlines at start and end
  * setting/adding correct language
  * converting from programlistings to screens

backport: havana

Change-Id: Idceefccf057abe43433a2ddd52743f8b7b960646
Merge "transforming listings to tables in chapter networking"