implement "lift" for modules

    i1 : lift ( (QQ[x])^3, QQ )
    stdio:1:1:(1):[0]: error: no method found for applying lift to:
			      3
	 argument 1 :  (QQ[x])  (of class Module)
	 argument 2 :  QQ

    i2 : lift ( id_((QQ[x])^3), QQ )

    o2 = | 1 0 0 |
	 | 0 1 0 |
	 | 0 0 1 |

		  3        3
    o2 : Matrix QQ  <--- QQ
