External builds need tsearch include files

I tried to compile a custom tsearch dictionary as an external module,
but it couldn't find the tsearch include files in the server
installation. tsearch subdirectory needs to be added to
src/include/Makefile, otherwise they don't get installed:

*** src/include/Makefile        9 Dec 2005 21:19:35 -0000       1.21
--- src/include/Makefile        10 Sep 2007 19:53:54 -0000
***************
*** 18,24 ****

  # Subdirectories containing headers for server-side dev
  SUBDIRS = access bootstrap catalog commands executor lib libpq mb \
!       nodes optimizer parser regex rewrite storage tcop utils \
        port port/win32 port/win32/arpa port/win32/netinet port/win32/sys

  # Install all headers
--- 18,24 ----

  # Subdirectories containing headers for server-side dev
  SUBDIRS = access bootstrap catalog commands executor lib libpq mb \
!       nodes optimizer parser regex rewrite storage tcop tsearch utils \
        port port/win32 port/win32/arpa port/win32/netinet port/win32/sys

  # Install all headers


--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com