Fix #16 Ruby pg gem fails to install

Fix a problem where the Ruby pg gem fails to install because it depends on
missing Postgres headers.

The missing dependency is libpq-dev on Ubuntu, postgresql-devel on Suse,
RedHat, CentOS.
Merge pull request #17 from mikeyp-dell/development

Fix #16 Ruby pg gem fails to install
starting to add CentOS 6.4
Merge branch 'master' of https://github.com/crowbar/crowbar-utils
small cleanup
most of the centos build box stuff done.