Do not write port config for apache twice (bnc#897996)

We were defining the template twice, which resulted in the file being
written twice, including once with some non-valid config.

Instead, just override the variable we need in the template the second
time.

https://bugzilla.suse.com/show_bug.cgi?id=897996
Wait not only until current chef-client is finished,
but also check the running queue of chef clients.

That way we make sure dhcp & PXE config are updated before reboot:
the chef-client run that was supposed to write these settings
might still be in the queue.
Add some comments to explain how we wait for chef-client on state change
Avoid race between chef-client queue getting emptied and chef-client run
Merge pull request #1 from vuntz/race-reinstall

Add some comments to explain how we wait for chef-client on state change
Merge pull request #1164 from jsuchome/wait_for_chef_clients

Wait not only until current chef-client is finished,
Merge pull request #1163 from vuntz/bnc897996

Do not write port config for apache twice (bnc#897996)
When a `$barclamp-$role_remove` role (and its removal recipe)
has successfully finished, delete it from the node's run_list.
Adding a specification of delete_remove_role_from_runlist