WIP: warning about cookie use, to comply with EU law.
Minor change in cookie warning styling.
Minor change in noscript warning text.
Put cookie notice at the bottom of the page. Minor change in spanish text.
Show cookies warning in the user profile page.
If a "accepted_cookies" cookie is set with value "true", do not show the cookie notice.

Also increase close button opacity in the cookie notice. It was too easy to overlook it, and I don't want user complaining about an undismissable cookies message.
Added a tooltip to the "accept" button in the cookies warning.
Added ngCookies module to the angularJS client, to be able to set/read cookies.
Implemented angularjs service to set the "accepted_cookies" cookie.

Not yet implemented: this cookie will be set with value "true" when the user clicks on the "accept" button of the cookies warning message. If this cookie is set to "true", the cookies warning message won't be displayed.
Renamed file.
When the user clicks on the "accept" button of the cookies warning message, a cookie is set to remember this fact.

If this cookie is set to "true", the cookies warning message won't be displayed.

Currently it is a session cookie. Pending: study if the $cookies angularjs service can be used to set persistant cookies. Also consider if changes to Path, HttpOnly and Security attributes of the cookie would be desirable.
Set cookie with document.cookie instead of $cookies.

This makes the ng-cookies module unnecessary, which reduces the downloaded javascript size.

The angularjs $cookies service does not allow changing cookies attribute, specially its expiration. It is hardcoded to save only session cookies. This is unacceptable for our needs, so we have to use other APIs to set cookies.
Set accept-cookies cookie to expire in the very far future (year 9.999).

It seems that Chrome ignores this date and instead sets the cookie to expire on 'Tue, 19 Jan 2038 03:14:07 GMT', which is the maximum date since Epoch expressed as an amount of seconds stored in a signed 32-bit integer. This shouldn't pose no problems.

Also set the Path explicitly to '/'. This should not be a problem, but it's better to be explicit.