Load packaging-specific versions in load_versioning also

It probably seems odd to load packaging-specific version
determinations, such as rpmversion here, at the top-level, and it is.
The reason for this that the creation of the most basic package
composition, the tarball, includes the generation of many different
packaging-specific files from templates in the source, and if faced
with loading rpmversion in the Tar object vs rpmversion in the
Config, I opt for the latter. It's basically a lose-lose, since it
really belongs in the Rpm object.

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>