core: Simplify the trace maros by using variadics.
* src/debug.h (TRACE_BEG, TRACE_LOG, TRACE_SUC): Use variadic macros and remove the TRACE_BEG1 et al. Change all users to always pass a format string. (TRACE): Ditto. * src/debug.c (_gpgme_debugf): New. * configure.ac <GCC>: Add -Wno-format-zero-length.
This makes it easier for use to enable format checks. The zero-length
format is required to allow for an empty format due to the comman
problematic of VA_ARGS.
- Signed-off-by: Werner Koch <wk@gnupg.org>