Update password

Basic validation of form fields (!empty and new passwords match)
Will test if current password matches for this user
Encrypts the new password with the same salt
Feedback provided after change attempt

<!---
@huboard:{"order":15.1875,"milestone_order":34,"custom_state":""}
-->

no need to check `err` again since you return if there's an error before. Speaking of which, if you get an error on the request, you don't set the message and styles