(Bug #21762) Update facter to support F19

This commit modifies the bild_defaults file to include fedora 19 in
the final mocks list. It also removes the ruby(abi) requirement, as
F19 no longer provides it.
Merge pull request #480 from melissaanne/maint/stable/re-47_f19-updates

(Bug #21762) update facter for f19 updates