Restructure builds to allow more flexibility

As a restructure, nothing is changed from the original behaviour and
naming despite the file structure changing. The symlinks to build had
to be updated generating lots of "deleted" and "new_file".

The new structure is:

docker/${base_distro}/${type}/${container}

base_distro == centos, ubuntu, fedora, etc
type == source, binary, rdo

type rdo is a symlink to binary for backwards compatibility

Two new flags are added to the build-all script to support the ability
to support different base distros and a flag to support binary or source
containers.

There are several added folders that are empty to hold the directory
structure for future containers of these types.

To use a prefix other than centos-rdo- you can set PREFIX in the toplevel
directory .buildconf file

Change-Id: Ifc7bac0d827470f506c8b5c004a833da9ce13b90