Fix disease group URLs on public site
Make disease group name fields unique, and remove non-unique data
Enforce disease group name uniqueness in the system administration page
Fixes following review
More fixes following review
Exclude blank values from uniqueness test (it's fine to have multiple nulls in a column)
Fix test
More test fixes
Add tests for violation of unique constraints
Merge pull request #182 from SEEG-Oxford/242-disease-group-unique

Enforce uniqueness of disease group name fields