Split shared code to helper function

(cherry picked from commit e308021396b3142e003d8c14a5ec911075207840)
Handle clusters in core of crowbar

We have a runtime dependency on the pacemaker barclamp here. If it's not
available, then we simply won't support clusters at all. If it's
available, we will use it to resolve clusters.

(cherry picked from commit 06d21aa60ae30f4f1f9d1c624a256bcf3996b46c)
Add helpers to get hostnames for OpenStack endpoints

This is common code that all barclamps need, so a helper is a good
thing.

(cherry picked from commit 7ee28dda3e4d6a2f72df09a93928746ee34e9ea6)
Integrated cluster selection into node selector

(cherry picked from commit e9c50efb74e48a93ab6b64c79076a930994ed8e3)
Understand cluster in template that we don't use

Just so we can say we've covered everything :-)

(cherry picked from commit 8d9a43a1d07c83c11f0a27e4d52c65e7af450e69)
Update after method moved in barclamp-pacemaker

(cherry picked from commit fd11e94006799b2380ce796b705a9537fe7e8f8f)
Fix hostname for virtual IP in admin network

It should not be prefixed with "admin.".

(cherry picked from commit 6ea82bf1fd6fca5bd0479a8068919c71b0c79a93)
Merge pull request #983 from vuntz/stoney-ha

Sync with roxy wrt HA integration code