NO-JIRA : added a hook inside caEditorInspector to allow plugin interaction

New hook is called hookAppendToEditorInspector, it requires an array as parameter (as usual), containing the object shown by the editor (object, entity, set...) as "t_item" ; it returns its parameter array augmented with a "caEditorInspectorAppend" with html to add under the inspector.
That allows to add side contextual function buttons through plugins.