Last names must be alphanumeric (plus - and _)

Annoyingly, having a last name like `O'Meara` will break Illumina's software, since it results in project names like `92_O'Meara_Boehm` in the sample sheet. I've editted that instance in the database, but the last name should ideally be check to ensure all characters are in [a-zA-Z0-9-_], since that's all Illumina will accept (why yes, this is a very stupid limitation).