[CentOS] Build Instructions, utils, used by CentOS team

Hello -

A few months back, I had a bunch of questions regarding hacking up a
centOS install, even going as far as editing comps, adding my own
packages as part od @base and @core install groups, etc etc.  It was
quite an adventure.

However, I haven't don it in a while, so naturally, I forgot a lot about it.

I'm trying to remember who it was that had forwarded me docs and scripts
used by the CentOS build team, including procedures and the like, which
would help me out with this.  This information would be an incredible
help to me, and I would very very much appreciate it if I could get my
hands on this.

Thanks for your time
-dant