Ensure polkit config is written for RHEL6 as well

Separate F18 polkit config and ensure it's written out for RHEL6, or
you get authentication errors with libvirt

Change-Id: I50c8a639337d171d94aa8a5a00b9f458efddbb6e
Grab upstream nodejs for RHEL6

RHEL6 has no nodejs in main packages or in EPEL.  The easiest way is
to just install the upstream binary version which works fine for the
very minimal usage by lesscss.

Change-Id: Ieea7aa21705e193a635d17e3963cc673cbd41c79
Basic check for homedir permissions

Several guides suggest using data directories under your homedir,
rather than the default /opt area.  This is fine, but on RHEL6 and
similar distros homedirs are very restrictive 0700 permissions which
doesn't allow things like httpd to pass through to serve up files.

Even though stack.sh is taking over the host, changing permissions
automatically is not a nice idea.  So we just warn when it looks like
this is happening.

Change-Id: I9cd70e7fe90638a2a5c3b8fd94756afacac7c7be