Adds second hiera data directory

This allows hiera data to be split into two buckets: sensitive and
non-sensitive. Sensitive data is put where it always has been. Non-
sensitive data, such as users ssh keys and lists of packages can be
put into the data directory contained within the
openstack-infra/config git repository.

This also introduces a more complex hierarchy: data is now split on
osfamily and lsbdistcondename. Operatingsystem is left for
compatibility.

Change-Id: I3b3faeab837aa5732da01e96bbe0c19aa936a58d
Merge "Adds second hiera data directory"