Deal with even more strange clocks, like those on NetBSD

Aparently, after a sleep of 2 seconds, the clock only increases a single
seconds...

http://www.cpantesters.org/cpan/report/f1cf98a2-6d39-11e2-b162-c5ed238b44f3

Signed-off-by: Pedro Melo <melo@simplicidade.org>
Prep 0.007 release

Signed-off-by: Pedro Melo <melo@simplicidade.org>
v0.007

        * Deal with even more strange clocks found by cpantesters