Removal of useless include references

It has been years since I ran src/tools/pginclude/pgrminclude to remove
unnecessary include files.  (I have already fixed things so include
files can be compiled on their own.)

The attached patch removes unneeded include references, and marks some
includes as needing to be skipped by pgrminclude.

I am sure applying this patch will break builds on some platforms and
some option combinations so I will monitor the buildfarm when I apply it
and make adjustments.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +