RFE: Add option to make osinfo less RHEL-centric and less focused on support issues

[ryran]

Basically, this means adding an environment variable and possibly an easy-access cmdline toggle to switch between rhel-centric support-concerns and normal linux mode. This will only affect the osinfo output.

When in rhel-centric mode:

• Special treatment for /etc/redhat-release
  • It's always shown, regardless of whether the file is there (glaring (missing) tag)
  • Special colorization for oddities in redhat-release
• RHN field always shown, with special colorization for a few oddities
• Colorization for kernel build version not being from a RHT build-server
• Some checks for RHEL-hybrids are automatically run -- i.e., to see if system has suse, oracle, centos packages installed

When in general linux mode, none of the above happens. Simple enough.