Use gcc pragmas to suppress some warnings.
* configure.ac (AH_BOTTOM): Add GNUPG_GCC_VERSION macro. * util/estream-printf.c (pr_float): Use new gcc pragma to ignore a warning about a non-literal format. * util/miscutil.c (asctimestamp): Ditto. * cipher/md.c (md_stop_debug): Use new gcc pragme to ignore a warning * about a set but unused variable.