** Renamed IllusionGroupUser* -> IllusionGroupMember*
** Changed IllusionGroupAvatarServlet to identify members by id instead
of userJid
** Generalized id, name, description, illusionFolderPath and
mayEditMaterials into AbstractIllusionGroupBackingBean from
IllusionGroupBackingBean and IllusionMaterialsBackingBean
** Added view for managing members
** Added support for inviting new members into Illusion groups
** Added menu item for Illusion group member management