feature #4195 Added a note about the total deprecation of YUI (javiereguiluz)

This PR was merged into the 2.3 branch.

Discussion
----------

Added a note about the total deprecation of YUI

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes
| Applies to    | 2.3+
| Fixed tickets | -

Maybe we could also close the related issue #1841?

Commits
-------

f5021d5 Fixed the official name of Node.js
d027c80 Added a note about the total deprecation of YUI

Author: weaverryan

cookbook/assetic/yuicompressor.rst

@@ -10,8 +10,13 @@ you can take advantage of this tool very easily.
 
 .. caution::
 
-    The YUI Compressor is going through a `deprecation process`_. But don't
-    worry! See :doc:`/cookbook/assetic/uglifyjs` for an alternative.
+    The YUI Compressor is `no longer maintained by Yahoo`_ but by an independent
+    volunteer. Moreover, Yahoo has decided to `stop all new development on YUI`_
+    and to move to other modern alternatives such as Node.js.
+
+    That's why you are **strongly advised** to avoid using YUI utilities unless
+    strictly necessary. Read :doc:`/cookbook/assetic/uglifyjs` for a modern and
+    up-to-date alternative.
 
 Download the YUI Compressor JAR
 -------------------------------
@@ -164,4 +169,5 @@ apply this filter when debug mode is off.
 
 .. _`YUI Compressor`: http://developer.yahoo.com/yui/compressor/
 .. _`Download the JAR`: https://github.com/yui/yuicompressor/releases
-.. _`deprecation process`: http://www.yuiblog.com/blog/2012/10/16/state-of-yui-compressor/
+.. _`no longer maintained by Yahoo`: http://www.yuiblog.com/blog/2013/01/24/yui-compressor-has-a-new-owner/
+.. _`stop all new development on YUI`: http://yahooeng.tumblr.com/post/96098168666/important-announcement-regarding-yui