Store transaction element pointers in the removedPkgs hash

Store transaction element pointers in the removedPkgs hash

- Change the hashtype name to something else, its no longer a plain
  int hash. Still needs double definition as its not contained in
  a single source (might want a wrapper similar to rpmal), but
  slightly more contained now than the previous intHash definition.
- This opens up some new possibilities, to be taken advantage of
  in later commits.