Factor configure_rhc out of install_rhc_pkg

For consistency with commit 48336e7e05ebf3d9d2d20d1975f4f005c9999928,
split configure_rhc out of install_rhc_pkg.
openshift.ks: Delete unused keyfile variable

configure_named: Delete the keyfile variable, which is defined but never
used.

The variable held the full path to the key file for BIND.  There is only
one place where we could use that variable, and it is clearer just to use
the full path there instead of $keyfile.
openshift.ks: Add set_conf

Add the set_conf function, which takes the filename of a configuration
file, the name of a setting, and a value for that setting and adds the
setting to the configuration file if it isn't already present with the
given value.

Add the set_sysctl function, which wraps set_conf for /etc/sysctl.conf.

configure_sysctl_on_node: Use set_sysctl and improve comments.

install_rhc_pkg: Use set_conf to set libra_server.

set_mongodb: Use set_conf.

configure_datastore: Use set_mongodb to set bind_ip.
openshift.ks: Install yum-utils if needed

configure_rhsm_channels: Install yum-utils before trying to run
yum-config-manager, which is shipped in the yum-utils package.
A minimal RHEL6 installation may not have yum-utils installed.
(Thanks for the report, Tim Hunt!)
Installing the admin console
Removing unneeded restorecon on mcollective files
openshift-cgroups is no more
generating the other install scripts
Merge remote-tracking branch 'miciah/openshift.ks-install-yum-utils' into enterprise-2.0
Merge remote-tracking branch 'miciah/openshift.ks-add-set_conf' into enterprise-2.0
Merge remote-tracking branch 'miciah/openshift.ks-drop-keyfile-variable' into enterprise-2.0
Merge remote-tracking branch 'miciah/openshift.ks-factor-configure_rhc-out-of-install_rhc_pkg' into enterprise-2.0

Conflicts:
	enterprise/install-scripts/amazon/openshift-amz.sh
	enterprise/install-scripts/generic/openshift.sh
	enterprise/install-scripts/openshift.ks
Allow the admin-console to be reached if the node and broker are on the same
machine

The user would still have to manually add the proxy pass to
000002_openshift_origin_broker_proxy.conf if they want to expose the admin
console outside of localhost.
Bug fixes for set_conf work