New User: generate defaul password

[vladsavchuk]

Suggest to generate default password on new user creation

With "show password" checkbox.

[osalabs]

Since we are going to store passwords encrypted in database, the whole process of work with passwords will be changed:

• forgotten password - will not send existing password to the user's email, instead it will send a link to "set a new password"...
• then "Add New User" from admin module could just always automatically generate a new password and send "welcome" email with a password once user added.
  • or it could generate password automatically only if password not entered.
  • then have a hint "if not entered, password will be generated automatically"
  • and then have a hint on "add new user" - "welcome email with login/password will be sent to the user"