fixtures for testing
trait controller test
modified edit trait
show flash error
modified unlinking covariate
code restyle
moved citation into rescue block
update trait controller
modified rendering
fixed error on trait/new
modifiy @new_covariates
Removed commented-out line.
Merge branch 'phenolphtalein-edit_trait-2'

This addresses Redmine issues #2351 and #2198 and the second part of issue #2245.