CSS adjustments for permision request text in message editor

Some CSS and JS fixes have been applied to the "You need permision to translate messages" label that appears for annonymous users:
* Adjust color and position of the texts (adding appropriate classes in JS)
* Make shortcut info not visible when users are no able so save.
The rationale for this is to avoid the shortcut message to compete for user
attention with the permission message.

Change-Id: Ie5320c4895ddc4b97de17233463620b5fb5f9a96