<install> don't always set the hostname

If the "hostname" specified is an IP, don't set that.
Also, if they don't want their hostname overwritten, there's an option
for that.
Also, superseding the hostname in the dhcp conf appeared to do nothing
(or be overwritten by sysconfig) so it's removed.
<install> ability to not create host DNS entries

Conflicts:
	enterprise/install-scripts/amazon/openshift-amz.sh
	enterprise/install-scripts/generic/openshift.sh
	enterprise/install-scripts/openshift.ks
<install> separate host DNS out from app

Conflicts:
	enterprise/install-scripts/amazon/openshift-amz.sh
	enterprise/install-scripts/generic/openshift.sh
	enterprise/install-scripts/openshift.ks
<install> ability to skip jboss repos/carts
Merge pull request #93 from sosiouxme/enterprise-2.0-DNS

aw, let 'er rip :)