2009-06-19 Marcus Brinkmann <marcus@g10code.de>

• libtool.m4: Removed.
• m4/libtool.m4, m4/ltoptions.m4, m4/ltsugar.m4, m4/ltversion.m4,

m4/lt~obsolete.m4: New files from libtool 2.2.6.

• configure.ac: Update to libtool 2.2.6.

(lt_cv_deplibs_check_method): Slightly evil hack to get libtool to
our thing.
(AC_DISABLE_STATIC, AC_LIBTOOL_WIN32_DLL, AC_LIBTOOL_RC)
(AC_PROG_LIBTOOL): Obsolete, replaced by ...
(LT_PREREQ, LT_INIT, LT_LANG): ... these new macro invocations.

• src/Makefile.am: Remove a bunch of rules for shared library.

(RCCOMPILE): New.
(LTRCCOMPILE): Use it here.
(.rc.lo): Add quoting.