Restyle the new and edit trait pages.
In the create and update methods, don't add new covariates to
@traits.covariates unless there are no save errors.  We want "View
Existing Covariates" on the new and the edit pages to show only the
saved covariates.
Merge branch 'phenolphtalein-restyle_new_edit'
Merge branch 'master' of github.com:PecanProject/bety