non-compact to_string
support more DOAP propeties
support doap:name for versions
make see_also lazy
support doap:Repository
use MooseX::AttributeTags for attribute tagging
check `does` instead of `can`
make Resource into a base class instead of a role

--HG--
rename : lib/RDF/DOAP/Role/Resource.pm => lib/RDF/DOAP/Resource.pm