Get FreeBSD 3.4 building again. It doesn't have lib dl, so the build

Get FreeBSD 3.4 building again.  It doesn't have lib dl, so the build
was broken as of the time we started always sticking in -ldl.

src/modules/standard/config.m4:

. don't add "-ldl" to LIBS for FreeBSD either
. back out previous change regarding LTFLAGS; it should be o.k.
  to add it for any platform, because libtool knows what to do with
  it (no, Greg A., I haven't added support for it to OS/390 libtool
  yet :) )

src/lib/apr/configure.in:

. if dlopen() isn't found in lib dl, don't fret (yet); try to find
  it in the default libraries;

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85505 13f79535-47bb-0310-9956-ffa450edef68