chore(client): Update "passwords are the same" error text.

fixes #736
chore(client): Update Throttled text to be more user friendly.

fixes #776
Merge pull request #848 from mozilla/issue-776-throttled-text

chore(client): Update Throttled text to be more user friendly.
Merge pull request #851 from mozilla/issue-736-password-text-update

chore(client): Update "passwords are the same" error text.
fix(client): transition from password reset confirmation to signin once reset is complete
fix(tests): Ensure enough test coverage for confirm_reset_password.