We had this interesting set of facts conundrum, according to vercmp
return values:
    2.0a <  2.0
    2.0  <  2.0.a
    2.0a == 2.0.a

This introduces a code change that ensures '2.0a < 2.0.a' as would be
expected by the first two comparisons. Unfortunately this stays us a bit
further from upstream RPM code, but those are the breaks (in RPM, the
versions involving 'a' do in fact compare the same, but they are both
greater than the bare '2.0').

Signed-off-by: Dan McGee <dan@archlinux.org>