oo-diagnostics: improve suggestion for mco-client.log

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

When noting that the mco client log permissions are wrong, we now
suggest they might just not want to log to a file at all.
oo-diagnostics: detect more common selinux problems

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements
There are some common SELinux labeling issues that we can catch here;
if we don't, then debugging the resulting problem can be really tricky.
The most annoying ones are when administrators copy a conf file to
their home dir or /tmp, edit that, and them move it back into place,
giving things like /etc/hosts or broker.conf the wrong label.
oo-diagnostics: warn re vmware-tools on mco unsynced warning

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

When vmware-tools is in place, it can conflict with ntpd in trying to
manage the host clock. Warn the admin if this may be happening (but only
if mco is already dropping expired messages).
oo-diagnostics: handle missing host command

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

Some of the more important tests depended on the "host" command.
This change causes them to fail gracefully when it's not there.
oo-diagnostics: warn on node.conf/envvars mismatch

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

Sometimes admins update their settings in /etc/openshift/node.conf but
don't realize that the gears get the same settings from
/etc/openshift/env vars. Check broker and cloud domain match.
oo-diagnostics: remove enterprise RPM test from origin

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

The test for OpenShift Enterprise RPMs really doesn't belong here.
We can just add it in at the Enterprise project.
oo-diagnostics: refactor test for executable commands
oo-diagnostics: detect unreadable apache conf files

https://trello.com/c/CBLIqG00/214-1-oo-diagnostics-improvements

Sysadmins were sometimes running through the deploy or post-deploy with
a umask such that the conf files being created were not readable by
apache. This can cause a lot of annoying problems. Try to detect this.
Merge pull request #4963 from sosiouxme/oo-diag-enhance

Merged by openshift-bot