Handle i.imgur for Imgur Extractor

This should fix #30

Also, adding i.imgur will add the title and/or description to direct
image link (could be interesting)

This will also perform more query to the Imgur API.
Add trigger_error when extractor fails
Fix Undefined extended_entities

This should fix this notice:

> Undefined index: extended_entities
One more fix for encoding content
Use ParamConvert to simplify controllers

Following "best practices"
Remove @Template annotation

And follow best pratice http://symfony.com/doc/current/best_practices/controllers.html#template-configuration
Update deprecated method

Following best pratices on Form: symfony.com/doc/current/best_practices/forms.html
Quick cleanup on Formatter

Define abstract method that weren't used in the main class
Use moment.js instead of KnpTimeBundle

Moved the front logic to javascript
Add more information in the public page:
 - link to the website
 - items in the feed
 - clear link to the readable feed
Fix tests
Handle Flickr photo set
Update deps
Add DeviantArt Extractor
Update comment for Flickr Extractor
Little issue for scrutinizer
CS
Update deps
Add Camplus Extractor

Fix #32
Merge pull request #33 from j0k3r/camplus

Add Camplus Extractor
Update deps

Symfony 2.6 :-)