Fixes compilation with -Werror=implicit-function-declaration .

Signed-off-by: Rosen Penev <rosenp@gmail.com>

This patch updates OpenLDAP to 2.4.47, introduces new build
parameters and places openldap-server, openldap-utils and
libopenldap under a separate menu item in Network.

OpenLDAP is difficult to find in menuconfig at present. Making
a separate menu item for OpenLDAP for selection of packages and
enabling or disabling build parameters makes better sense.

To have access to the loglevel directive, OpenLDAP must be built
with debugging information. Having access to the loglevel directive
is essential during the initial configuration of OpenLDAP server.

International users may want to enable ICU support to have access
to international characters.

Signed-off-by: Val Kulkov <val.kulkov@gmail.com>

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Such information from the build system break reproducible builds.

Signed-off-by: Alexander Couzens <lynxis@fe80.eu>

At least one LEDE buildbot is missing tools to create man pages, thus the build
sometimes (depends on which buildbot is used) fails with [1]:

-snip-
make[7]: Entering directory '/mnt/build-dir/lede/armeb_xscale/build/sdk/build_dir/target-armeb_xscale_musl-1.1.15/openldap-2.4.44/doc/man/man1'
PAGES=`cd .; echo *.1`; \
for page in $PAGES; do \
    sed -e "s%LDVERSION%2.4.44%" \
	-e 's%ETCDIR%/etc/openldap%g' \
	-e 's%LOCALSTATEDIR%/var%' \
	-e 's%SYSCONFDIR%/etc/openldap%' \
	-e 's%DATADIR%/usr/share/openldap%' \
	-e 's%SBINDIR%/usr/sbin%' \
	-e 's%BINDIR%/usr/bin%' \
	-e 's%LIBDIR%/usr/lib%' \
	-e 's%LIBEXECDIR%/usr/lib%' \
	-e 's%MODULEDIR%/usr/lib/openldap%' \
	-e 's%RELEASEDATE%2016/02/05%' \
	    ./$page \
	| (cd .; soelim -) > $page.tmp; \
done
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
/bin/sh: 15: soelim: not found
Makefile:292: recipe for target 'all-common' failed
make[7]: *** [all-common] Error 127
-snap-

For OpenWrt/LEDE, there is no reason to build the tests and/or man pages,
so let's patch it away. And since other packages need openldap as
build dependency (e.g. php) this automatically fixes the build of these
depended packages.

[1] https://downloads.lede-project.org/snapshots/faillogs/armeb_xscale/packages/openldap/compile.txt

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Signed-off-by: W. Michael Petullo <mike@flyn.org>