Add 500px and Searchcode engines

Allow to search for images on 500px. It doesn't use the official API, but the page result. Less stable, but less API key to possess...

Two engines were necessary for Searchcode because there are to search mode : search for documentation or search for code example. Both use open APIs.

[fix][enh] Multiple JS changes in Oscar

[enh] add photon engine, and fix pep8 errors

Definitely remove engine array
Change every themes to accomodate that change
Tweak of video template of oscar to add link on video thumbnail

Conflicts:
	searx/engines/flickr.py
	searx/settings.yml

It uses the webpage json infos to build the results
Let the user choose the engine in setting.yml. Noapi active by default
+ little corrections on Flickr engine

[fix] fix kickass engine

thanks @Cqoicebordel in #144:
https://github.com/asciimoo/searx/pull/144#issuecomment-67036903

[enh][oscar_template] replace kickass icon

Everything was redone to use the API. It needs an API key, but it's worth it.
Everything works. Title, Image, Content, URL
The API allow lots of things. Thumbnails and date will be easy to add when it will be implemented in Searx.

Fix asciimoo/searx#126

Everything was redone to use the API. It needs an API key, but it's worth it.
Everything works. Title, Image, Content, URL
The API allow lots of things. Thumbnails and date will be easy to add when it will be implemented in Searx.

Fix asciimoo/searx#126

Kickass torrent search engine

Add kickass in engine list
Add content for the result from kickass

Html+Bugs in templates

Add the alt in favicon

Add for the template a list of available icons in the current theme.

Alt on favicon
No <p> in <p>
Correct alt and title on img

Put the result URL at the top, like in other results template
Put the magnet link on the same line as the stats (peer/seed).