Build system improvements

- Use AM_GLIB_GNU_GLIB and IT_PROG_INTLTOOL
- Use gnome-autogen.sh
- Move language list to own file
- Delete generated config.rpath file

.gitignore

@@ -36,7 +36,7 @@ plugins/perl/hexchat.pm.h
 po/Makefile.in.in
 po/POTFILES
 po/remove-potcdate.sed
-po/stamp-po
+po/stamp-*
 data/pkgconfig/hexchat-plugin.pc
 src/common/dbus/example
 src/common/dbus/marshallers.h