Utchw support

Summary: Add support for the UTC={yes,no} configuration parameter in the /etc/sysconfig/clock file.  Also add comments at the top of the clock and timezone templates stating that they are managed by Puppet.

Our current /etc/sysconfig/clock file explicitly states UTC=true, and I didn't want to assume that we could just remove the entry and use the default.  Also, there could be outlier cases where systems need UTC=false.

The same appears to apply to Debian systems, but since I don't have anything except RedHat for testing, I did not update timezone.erb (or related spec files), and I noted in the usage that the setting only applies to RedHat for now.

Ubuntu docs: https://help.ubuntu.com/community/UbuntuTime
CentOS 5.x docs (I had trouble tracking down 6.x docs): https://www.centos.org/docs/5/html/5.2/Deployment_Guide/s2-sysconfig-clock.html

I also added a comment line at the top of the templates to state that the clock / timezone files are being managed by Puppet (I noticed that there was an open issue, and it was a simple change).

Please note that this is my first pull request, and I do not have a great deal of experience with Puppet and spec coding as of yet.  Please test the changes I am suggesting.