CentOS 7 packages for the SP are available

[Cantor, Scott]

I've updated the Linux RPM doc page with some changes and the packages
should be making their way to mirrors.

http://download.opensuse.org/repositories/security:/shibboleth/CentOS_7/

As I noted in the documentation, these packages are the only ones I can
make available for Red Hat 7, the build service no longer has access to
enough of the package set from Red Hat to make building on it work.
However, I've tested these on Red Hat 7 and they seem to work so far,
which is to be expected. I'm sure that's the case with older versions too,
it just didn't ever become a necessity to check.

Also, do not expect tight integration. I have bugs open on the init.d to
systemd change and I noted a possible change in how the integration with
Apache is supposed to work, but nothing that prevents it working.

-- Scott