Ansible launcher: fix afs publisher
Ansible launcher: fix afs publisher

This contains several fixes:

* Support remove-prefix.  This is used by the FTP publisher we are
  replacing.
* Fix sed expressions.  They were missing a '/'.
* Make the target directory before rsync.  Rsync requires the target
  root directory exist before running.  Elsewhere we solved that by
  encoding the mkdir into the remote rsync command.  Since we are
  running locally here, just run 'mkdir -p' before running rsync.
  However, it must be done with the keytab, so include it in the
  k5start command (so that we do not need to run k5start twice).
* Include the 'user' in the site definition as the principal for
  k5start.

Change-Id: I69c263a35e732b9a21d411bd30215945783d1023

gooddata/zuul,gooddata/zuul,gooddata/zuul,gooddata/zuul,gooddata/zuul