Adding installation of more rpm packages.

Added the following rpm packages:
pixman libXfont libX11 perl-Params-Validate perl-Time-HiRes

Made the optional group packages into separate installs
so we can more easily see which one failed.

Changed the EPEL rpm installation to use wget which will timeout
if unable to reach the download site.  The previous method of
using rpm directly could hang forever.

Change-Id: Ifad64df0f6ba493877ce777890ab17a8b193a3ff