Added fastclick in an attempt to break the 300ms barrier on tablets.

* Enforce the separation between css and js selectors (classes for
  css and ids for js)
Typo on thumbnails dimension.
New visual indicator during loading of the content in an infinite scroll.
New doc on the development of the website.
Disabled JSHint warning concerning the number of statements in the Grunt file.
New print stylesheet. Preparing for release 1.5.