core: Prepare to build with gpgscm.
* configure.ac: New option --enable-gpgscm. Create gpgscm/Makefile. (GPGRT_ENABLE_LOG_MACROS): Define. * Makefile.am (SUBDIRS): Add gpgscm * src/logging.c (_gpgrt_logv_clock): Do not use the log_debug macro.
Note that gpscm does not yet build.
- Signed-off-by: Werner Koch <wk@gnupg.org>