Extend TyCons and DataCons to represent data instance decls

Extend TyCons and DataCons to represent data instance decls
Mon Sep 18 19:05:18 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
  * Extend TyCons and DataCons to represent data instance decls
  Fri Aug 18 19:11:37 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
    * Extend TyCons and DataCons to represent data instance decls
    - This is a faily involved patch, but it is not entirely complete:
      + The data con wrapper code for instance data cons needs to apply the
        coercions (which we still have to generate).
      + There are still bugs, but it doesn't seem to affect the compilation of
        code that doesn't use type families.

    ** WARNING: Yet another change of the iface format.  **
    **          Recompile everything.                    **