make MedicTerm a subclass of DiseaseTerm
Fixed a bug in our model. (Unused field, but still...)
Added annotationExtension to evidence class.
Add cell lines to genotypes.
add reverse-references
Merge branch 'dev' of git://github.com/mgijax/mousemine_bio_sources_mgi into ExpressionDumper
change expressions to expression
Merge branch 'ExpressionDumper' into dev