fix relationship has and is
minor fixes to person and group
update relationship and relationship type
edit intro in README
change valnet link in README to reference wiki
add Quantity, Unit, and Kind from QUDT ontology
add symmetric property to Relationship based on discussion in #3
add .'s to descriptions
add .'s to descriptions
Merge pull request #4 from openvocab/relationship

update Relationship and RelationshipType
Merge pull request #5 from openvocab/qudt

add Quantity, Unit, and Kind from QUDT ontology
update README based on new vocabs
update README to include reference to valnet's core model
update README links
clarify intention in README
lay out basic roadmap through README
add checkboxes to vocab categories in README
fix link to ResourceType in README
list *Types first in README
Merge remote-tracking branch 'upstream/master'