** Added base class for workspace node events
** Added event classes for workspace material update & create events
** Changed WorkspaceMaterialController to fire a event when material is
created
** Added base classes for workspace folder and workspace root folder
events
** Added event classes for create & update of workspace root folder
** Added base classes for workspace folder update & create events
** Added events into workspace folder and workspace root folder create
methods in WorkspaceMaterialController
** Moved workspace material field creation into
WorkspaceMaterialCreateListener from WorkspaceHtmlMaterialBackingBean