Extension of Wayne's commit r5489 to reject blank usernames (as in made of space type chars only), e.g:

pho27:iRODS antoine$ iadmin mkuser "   " rodsuser
pho27:iRODS antoine$ 
pho27:iRODS antoine$ 
pho27:iRODS antoine$ iadmin lu
rodsBoot#pho27
rods#pho27
   #pho27
pho27:iRODS antoine$ 
 


git-svn-id: svn://irodssvn.ucsd.edu/trunk@5491 ea137bd6-aa86-47b6-b90d-b101d9f19a90