Fixes #1780 - changes EPEL url from download.fedoraproject.org to dl.fedoraproject.org

update default provisioning templates

• removed workarounds for RHEL3-4
• use bootif=<host mac> for RHEL hosts
• tried to do time sync against ntp-server parameter
• switched to using epel snippet instead dead epel code
• fixed #1487 - EOF sometimes not found

fixes #1669 - epel is now a snippet.

This adds another method to install the epel repo, as a snippet,
allowing users to customly change the url, in case that it doesn't fit
their needs or if the url changes again.

to use, simple use:

<%= snippet "epel" %>