fix to correctly set handle setting the suggested assay/tech type

assay now intercepts the assay/tech type being set, and handles the case
where it represents a suggested type
moved monkey patching of OntologyClass out of assay and turned into a concern
check for label should be case insensitive
Using ruby 2.1.5
updated incorrect comment about db:seed

it does not override running db/seeds.rb but runs it in conjuction with it