add support for rhel7
Merge pull request #672 from chjohnst/master

add support for rhel7
Add support for importing rhel4AS

Support importing Red Hat Enterprise Linux 4 AS.
This patch wasn't never submitted after closing the issue #387
https://github.com/cobbler/cobbler/issues/387
Merge pull request #673 from angystardust/patch-1

Add support for importing rhel4AS