Popup, Menu icons, Contextprocessor

* Popup; now can implement function to execute just before the popup
closes (for example remove classes, like what could happen in the
gallery)
* Menu icons; temporarily used menucontainer icons for menu item article
and custom menu item
* Contextprocessor access can be managed by action
"nxs_iswebmethodallowed" too
* Isolated injecting jquery to centralized place