restricted fields implementation

[handemcginty]

this is two parts:
first, for UCSF (and probably AZ) we need to be able to have limited-vocabulary fields
second, we need some kind of a warning system (that way we don't necessarily prevent users from picking whatever they want) that tells me "you picked binding for assay type and then you picked cell cycle assay as your bioassay"..

[mkoatwork]

Hi handemcginty,
we have the same problem and are intersted in developing a solution. If interested I could share our thoughts.