Log message:
Change the format of BUILDLINK_ORDER to contain depth information as well,
and add a new helper target and script, "show-buildlink3", that outputs
a listing of the buildlink3.mk files included as well as the depth at
which they are included.

For example, "make show-buildlink3" in fonts/Xft2 displays:

	zlib
	fontconfig
	    iconv
	    zlib
	    freetype2
	    expat
	freetype2
	Xrender
	    renderproto

Log message:
Track information in a new variable BUILDLINK_ORDER that informs us
of the order in which buildlink3.mk files are (recursively) included
by a package Makefile.

Log message:
Include options.mk in -client and -server, but not the common
Makefile.

Log message:
Import databases/openldap-client, formerly a part of databases/openldap but now
split off.  This package contains only the client tools and libraries, and the
manpages.  

LDAP-based applications should depend on this package, not databases/openldap
(anymore).