[fix] Google image with special chars

It seems like Google image is doing a double urlencode on the url of the images. So we need to unquote once before sending to the browser the urls.
It solves the 404 we could see with some image with specials chars in url. 
Exemple https://searx.laquadrature.net/?q=etes&pageno=1&category_images (there are two of those in the list)

Strip HTML tags on alt and title of the images

Add alt on favicon.
Use correct datetime format
Remove pubdate tag
Use url instead of pretty_url for web.archive.org
Add alt on video image

Add alt on favicons
Use correct datetime format
Remove pubdate tag
Use url instead of pretty_url for web.archive.org

Add alt on favicons
Use right format for datetime
Remove pubdate tag

Add title on image for hover
Add alt on favicon

Add alt for favicon
Correct datetime format
Remove pubdate (not in html5 spec)
Don't use pretty_url for web.archive.org.

Add alt in infobox image.

Put the infobox first. Result first is more useful for the user.
Add id in form for "for".
htmlentities in the URL.
Take care of spaces in categories.

Add pubdate with a good format, against publishedDate.

pep8 : engines

[oscar_template] split up js-files, FIX #132

Adding `import sys` to fix the installer

update of french translation

[fix][template_oscar] make overpass-api call over https and add better error-message

responsive theme courgette

and add better error message if ajax-call fail

Template oscar, add map support

[enh] make version of searx readable

change package data in setup.py for oscar theme

new template: oscar