Updated dns testsuite according real world example.
Updated DNS::ResolveIP to be strictly according hosts documentation.

Original implementation had two bugs. Firstly, it stripped a part of
hostname if it started by number. This one was fixed alredy.
Secondly, it didn't handle FQDN names - it didn't stripped domain
part, so the returned hostname was invalid in such case. It is fixed
now.

Also see bnc#813232
Updated changelog.