Translation preparation and spanish language.
Merge commit '68f9aabb4190100d6790be4180d938d22ce576a3' into i18n

Conflicts:
	torrents/blueprints/files.py
Links to change language.
Translation fixes.
Translation fixes.
Translation fixes.
Translation fixes.
Meta header for language alternatives.
Better url_for function.
Fixes on translation files.
French translation files.
Fix on url_for use.
Translation fix.
Translation fix.
Downloader installed translated.
Reverted support language at URL.
Error pages translations.
Changed lang attribute in HTML element.
Merge with master changes.
Better i18n for votes.