Added a form inside the user management to let admins register new users. These new users will be automatically approved and automatically have their email confirmed.

refs #1361

Conflicts:
	app/views/institutions/new.html.haml
	config/locales/en/mconf.yml
	config/locales/pt-br/mconf.yml
tests for admins controller

refs #1361
Update admins_controller.rb
Some improvements to let admins register new users.

refs #1361

Conflicts:
	app/controllers/users_controller.rb
Remove reference to 'institution' from users/new

refs #1361
'new_user' to 'user' and 'create_user' to 'create' in UsersController

Use default action names instead of custom names.

Changed devise routes for registration to be scoped to /users/registration,
so the standard actions in the scope /users can be used by UsersController.

refs #1361
Suggest a user ID when an admin is creating a new user

The same way it's done when a user is registering.

refs #1361
Fix redirects after changing registrations path to /users/registrations

Routes on /users/registrations were not being ignored on redirects.
Also changed the solution to #888: now there's a "blacklist" of routes on
SessionLocalesController for URLs we should not GET.

refs #1361
refs #888
Remove unnecessary rescue_from from UsersController

refs #1361
Fix missing messages on UsersController#create

refs #1361
Merge pull request #70 from mconf/feature1361-admin-form-register-users

Form for admins to register new users, #70 
refs #1361