Increase max length of institute identifier to 255

Change-Id: I94939aac6309956db0beb5dce06d7836d512cdd3
Increase max length of account username to 255

Change-Id: Ife65caffbfe3ee80d4bfafce0c039a8edb9644be
Increase the max length of group name to 255

This unifies all of the group identifiers to 255.  Any max length
requirement can be added back and controlled through a form.

Change-Id: I2364da7eebfc82fa076429d21dd96d9c4127e3b3
Increase the max username length to 255

I expect that the backend you select should determine the max length ofyes
a username.  This should probably be enforced at the form level, and the
max length should be made configurable.

Change-Id: Ief55c664bd2565b6db3f358690d2dd27df332e72
Increase application username length to 255

Change-Id: I6c2fefad4c70920e425b164e93d8d4ebbf262b4d