1. Make 'all' works without complaint.  Don't have to add the .exp
   files to the files list.  They are made automagically when
   making the respective shared lib file.

   Only port that actually uses EXPSUFF (from makefiles/Makefile.*)
   is Aix, so if this breaks anybody else, let me know, asap.

2. Make 'clean' actually cleans up correctly.  Previously, it would
   leave the .o files in C-code directory.

3. Changed references to reflect new location of .c files.

4. Added DELETE statements to complex.source so that it tidies up
   when done.  Previously, it would leave things in pg_amop,
   pg_amproc and pg_opclass.  Only possible to do this with the
   new SUBSELECT code in 6.3.  Nice work, fellas...

   Not deleting the index entries would cause a non-fatal error if
   complex.sql was run again on the same database.  Much tidier now.

5. Corrected the README.  obj directory hasn't existed since Bryan
   redid the make way back when.  Also changed the snipet from psql
   to match the current version. POSTGRES95?!?  I don't think so. :)