pgsql: Remove support for bcc and msvc standalone libpq builds

Remove support for bcc and msvc standalone libpq builds

This removes the support for building just libpq using Borland C++ or
Visual C++. This has not worked properly for years, and given the number
of complaints it's clearly not worth the maintenance burden.

Building libpq using the standard MSVC build system is of course still
supported, along with mingw.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/6da56f3f84d430671d5edd8f9336bd744c089e31

Modified Files
--------------
doc/src/sgml/install-windows.sgml | 117 ----------
src/Makefile.shlib | 16 +-
src/bcc32.mak | 47 ----
src/bin/psql/command.c | 4 -
src/include/getaddrinfo.h | 2 -
src/include/port.h | 2 +-
src/include/port/atomics/generic-msvc.h | 1 -
src/include/port/win32.h | 31 +--
src/interfaces/libpq/bcc32.mak | 312 ---------------------------
src/interfaces/libpq/win32.h | 8 +-
src/interfaces/libpq/win32.mak | 366 --------------------------------
src/win32.mak | 32 ---
12 files changed, 8 insertions(+), 930 deletions(-)