Change the representation of export lists in .hi files
Currently export list in .hi files are partitioned by module export M T(C1,C2) N f,g In each list we only have OccNames, all assumed to come from the parent module M or N resp. This patch changes the representatation so that export lists have full Names: export M.T(M.C1,M.C2), N.f, N.g Numerous advatages * AvailInfo no longer needs to be parameterised; it always contains Names * Fixes Trac #5306. This was the main provocation * Less to-and-fro conversion when reading interface files It's all generally simpler. Interface files should not get bigger, becuase they have a nice compact representation for Names.