Charms for centos - lets begin

This is the normal ubuntu package that brings in make and other build tools like a compiler on Ubuntu. It lets you bring in Python deps and have the start of the tools needed to build ones with c-modules.

@cory_fu is the main driver but this is really interesting feedback for him as well as folks like @jameinel as they work on improving the charming experience. This idea of Juju providing some sort of bootstrap on the units as we standardize is interesting. The main issues would be delivery since we would want to change/improve that bootstrap w/o having to be too tied to juju releases themselves though.