[ajax js/css] modconcat fix: load code exactly once (auc, fcayre)
* introduces cw.ajax namespace (currently hosts only recent modconcat functionality)
* handle load-one/load-many-at-once edge case
* properly handle already-loaded js resource
* avoid .appendTo to trigger script evaluation since from jquery 1.5 this results in uncached ajax calls
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html