Bump automake dependency to 1.13
Bump automake dependency to 1.13

Since we dropped ACLOCAL_AMFLAGS in Makefile.am we should depend on automake
1.13 (since this is the version that supports using AC_CONFIG_MACRO_DIRS
directly).

GNOME/dconf,GNOME/dconf,GNOME/dconf,GNOME/dconf