Perl version support policy = 5.8.1+ but accept 5.6 patches.
Fix empty versions for v5.6.2
Merge pull request #124 from mohawk2/perl56policy

Perl version support policy = 5.8.1+ but accept 5.6 patches.
Update bundled ExtUtils::Manifest to 1.65
Up the required version of ExtUtils::Manifest for packagers too