web: implement handlers for adding and updating admin accounts
web: implement handlers for adding and updating admin accounts

unique identifier is now the username and it is mandatory
both for additions and updates.

Signed-off-by: Ilija Hadzic <47a09d4a4430975766160361f65fc72633be50b6@gmail.com>

ihadzic/jim,ihadzic/jim,ihadzic/jim