gettext

74a9fca3 - build: Fix a build failure with bison < 3.0 when cldr-plural.y is modified.

build: Fix a build failure with bison < 3.0 when cldr-plural.y is modified. * autogen.sh (GNULIB_MODULES_TOOLS_FOR_SRC): Add bison. * gettext-tools/configure.ac: Don't invoke AC_PROG_YACC. Instead, invoke gl_PROG_BISON, set YACC, and invoke gl_BISON.