ltdl, remove unsusd check for ltdl.h
ltdl, move SXE_CHECK_LIBLTDL to configure.ac

autoreconf likes to see this in configure.ac. Most important It failed to
recongnice the LTDL_INIT mode, which is needed to guess the right
libtoolize options.
ltdl, use LTDL_INIT's "recursive" mode

This decreases the distdir size about 1.3 MB and increases configure
speed.
ltdl, workaround libtool LT_CONFIG_H bug

Building embedded libltdl fails because config.h is located in
subdir src. See libtool bug #12262
http://lists.gnu.org/archive/html/bug-libtool/2012-08/msg00007.html
Merge remote-tracking branch 'rudi/bld/ltdl' into next

* rudi/bld/ltdl:
  ltdl, workaround libtool LT_CONFIG_H bug
  ltdl, use LTDL_INIT's "recursive" mode
  ltdl, move SXE_CHECK_LIBLTDL to configure.ac
  ltdl, remove unsusd check for ltdl.h
(Partial) Revert "ltdl, move SXE_CHECK_LIBLTDL to configure.ac"

This reverts commit b8a9f69c9d1fde6745b641925641b0a0dd77d61e.

I like my stuff hidden away in macro files, so move the changes
made in ca1d2e9b and 63ae0eef back into a macro called
SXE_CHECK_LIBLTDL.

Signed-off-by: Sebastian Freundt <freundt@fresse.org>

Conflicts:
	configure.ac
Merge branch 'bld/dist' into next

* bld/dist:
  (Partial) Revert "ltdl, move SXE_CHECK_LIBLTDL to configure.ac"
chore, import latest sxe-compiler.m4 macro package

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
Merge branch 'bld/dist' into next

* bld/dist:
  chore, import latest sxe-compiler.m4 macro package
Merge branch 'next'

* next:
  chore, import latest sxe-compiler.m4 macro package
  (Partial) Revert "ltdl, move SXE_CHECK_LIBLTDL to configure.ac"
  ltdl, workaround libtool LT_CONFIG_H bug
  ltdl, use LTDL_INIT's "recursive" mode
  ltdl, move SXE_CHECK_LIBLTDL to configure.ac
  ltdl, remove unsusd check for ltdl.h