Currently we have many places where we serve resources with pipelines like "resources/**".
(kernel, each workspace, skin, skin/templates, etc...)
The issue is that thoses pipelines are different every where (handling js, locale.js, sass, less, image resizing...)

Add a new multiple extension point for handling resources (safe).
An extension would be able to describe:

• suffix handled (".js", ".toto.js", ".png", ""...)
• key cache/validity
• mime-type,
• content-length (if easy to compute)
  We have a default impl handling a classic Source (suffix "").
  All existing pipelines should now use a new reader that delegates to the extensions (sorted by handled suffix length desc : ".toto.js", ".js", "").
  BUT existing pipelines must kept ther specificity such as a <act type="plugin-exist">
  and pipeline simply transmit their path prefix "such as plugin: {1}

  //resources/"

Additionnaly we have existing reader that should be merged/destroyed/refactor ? such as RuntimeResourceReader & AmetysResourceReader

Additionnaly the flipbook that can display the first pdf page should use this new mecanism to do so (so it must be able to generate a pdf from any source) with an new url such as ".pdf.jpg" (note that this one should extend the classic .jpg to have resize features - and if the .pdf does not exists try to display the existing jpg image).

We have to check if minimizer still works and still have its cache working.