The fixes uses the patch provided by Pieter Palmers on the bug #489
description[1].
A very simple test, to check the signature existence, was added.
[1] http://bugs.openbossa.org/show_bug.cgi?id=489
Reviewed by Hugo Parente <hugo.lima@openbossa.org>
Reviewed by Luciano Wolf <luciano.wolf@openbossa.org>
