pgsql: Allow win32/cygwin link against the first matching library symbol

Log Message:
-----------
Allow win32/cygwin link against the first matching library symbol rather
than erroring out. This is the Unix behavior.

Modified Files:
--------------
pgsql/src/bin/pg_dump:
Makefile (r1.57 -> r1.58)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/Makefile.diff?r1=1.57&r2=1.58)
pgsql/src/template:
cygwin (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/template/cygwin.diff?r1=1.4&r2=1.5)
win32 (r1.2 -> r1.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/template/win32.diff?r1=1.2&r2=1.3)