Vendor specific -release files are deprecated in favor of generic /etc/os-release files.

Fedora, openSUSE, RHEL, and SLES already ship /etc/os-release.

See http://www.freedesktop.org/software/systemd/man/os-release.html
for details about this file.

This patch adds inventory/linux.cf to parse the ID and VERSION_ID
fields of os-release and adds global classes for <ID> and
<ID>_<VERSION_ID>

It also adds inventory/suse.cf to distinguish between SUSE Linux
Enterprise and openSUSE.
inventory/debian.cf: remove os_release_info, it is in inventory/linux.cf now
inventory/suse.cf: use | instead of ||
promises.cf: use | instead of ||
Merge pull request #191 from tzz/suse-inventory

SUSE inventory