[SHRINKRES-114] version range resolution support - v2

https://issues.jboss.org/browse/SHRINKRES-114

Rebased continuation of https://github.com/shrinkwrap/resolver/pull/45 .

Concerning last @ALRubinger message for 1) and 3) additional tests were added. Concerning 2)  I'm not sure if I rember the described problem correctly. If I rember my motivation lying behind implemented decisions a few months ago, it seemed that it was not possible to build this stage hierarchy other way, to allow to decide if user wants to resolve some dependencies or dependency version, same time limiting possible operations after version resolvment.