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(tests): Fix test failures by reducing shared global state.

* Completely clear Session, localStorage, and sessionStorage before and after every test.
* In the FxaClientWrapper, add `testClear` to clear global state.
* Minimize possibility of FxaClientWrapper collisions by using wrapper that is created by the views.

fixes #863
fix(tests): Use `assert(false, <message>)` instead of `assert.fail(<message>)`.

* The latter is incorrect usage according to the Chai docs.

fixes #861
chore(client): `Password` placeholder is changed to `New Password`

fixes #780
fix(client): Use sentance casing on placeholder text.

fixes #855