Need way for admin to change a user's password

Background

In Reference Application 2.3, in the Admin UI module, we intentionally do not allow an admin to set another user's password (principle of "non-repudiation"), even though this was previously allowed in the Legacy UI.

However, per complaint by arbaughj, we are being too strict: in real life there needs to be some way to unlock a user account if the user has forgotten their password and secret question/answer.

Acceptance Criteria

1. On the Edit Account page (e.g. http://demo.openmrs.org/openmrs/adminui/systemadmin/accounts/account.page?personId=4) for someone that has a user account, there should be a Reset Password button
2. Clicking the Reset Password button should pop up a confirmation dialog
3. If you say Yes to the confirmation dialog, then
   1. the user's password should be set to a new random password
   2. the "need to change password" flag should be set to true for the user
   3. the auto-generated password should be displayed on the screen with instructions telling the admin to communicate this to the user for a one-time login, then they can set their own password.
   4. a line must be written (at INFO level) to the log file saying which user changed the password of which other user
4. Create another ticket (with a barebones description), for a future release, about capturing email addresses for users, so they may safely reset passwords themselves.

See: https://talk.openmrs.org/t/how-can-an-admin-change-a-users-password/3342/5