Require pkg-config 0.26 or later (Bug#17438).
Earlier versions are buggy, as pkg-config --libs can output
nothing, which causes xrandr link failures.
- * configure.ac (PKG_PROG_PKG_CONFIG): Bump from 0.9.0 to 0.26.
+ * autogen.sh (pkg_config_min): Make this at least 0.26.
2014-05-07 Glenn Morris <rgm@gnu.org>