(FACT-637) Add lsbminordistrelease fact

This fact gives the minor version of the distro as derived from
lsbdistrelease and is confined to the kernel value of Linux or
GNU/kFreeBSD. Given lsbdistrelease of X.Y or X.Y.Z it will return Y. If
no minor version is present, the fact will not exist.
(FACT-637) Add lsbminordistrelease to facter schema
Merge pull request #741 from ghoneycutt/fact-637_add_lsbminordistrelease

Fact 637 add lsbminordistrelease