Id change password

# Change Password

![changepassword](https://cloud.githubusercontent.com/assets/1170410/2717512/710406e8-c541-11e3-9e85-d9970d0ba5fd.png)

Part of nextgen-r2 feature parity, this piece adds a change password page to nextgen identity.

Submitting the form will either produce an error on the relevant form field or redirect you to a success page with links onwards to edit your profile or go to the home page.

If a user has registered via social signup then they may not have a password so we have accounted for that in the template rendering.

The Scala portion of this work was by @Nick-Smith and I did the templating.