Add a timeout around snomed lookup field events
Add a timeout around snomed lookup field events

- Prevents too many XHRs from being issued as each character is entered.
- Clears the previous results.
- Notifies when a term matches no results.
- Requires at least 3 characters to search.

airslie/renalware-core,airslie/renalware-core,airslie/renalware-core,airslie/renalware-core