Reviews translate admin 764462

This solves the [bug 764462](https://bugzilla.mozilla.org/show_bug.cgi?id=764462) after being reopened.
**Public users**: text from review is translation via a redirection (no more ajax and Google API call).
**Admin users**: click to translate replaces the text (see the screenshots).

#### Before clicking:
![before clicking translate](https://f.cloud.github.com/assets/145172/1565769/47b89f6a-5084-11e3-8ef6-e8a6c015ad90.png)

#### After clicking:
![waiting for translation](https://f.cloud.github.com/assets/145172/1566333/99cfd846-508d-11e3-9996-9350cac29627.png)

#### When translation is retrieved:
![after clicking translate](https://f.cloud.github.com/assets/145172/1565770/4a360606-5084-11e3-929c-d7a4f99c02ad.png)

#### If some error occured:
![error translating](https://f.cloud.github.com/assets/145172/1566517/3f2e482a-5090-11e3-8d67-b8ee8c8dc846.png)