Update ignore list.

Include additional, automatically generated Autotool files.
Specifically, condense all 'config.*' files down to a single, glob
pattern.  Also, ignore all of Libtool's M4 macros in the 'm4' directory.

.hgignore

@@ -21,17 +21,13 @@ Doxyfile.in
 aclocal.m4
 am
 autom4te.cache
-config.h.in
-config.h
 configure
-config.log
-config.guess
-config.sub
-config.status
-config.lt
+config.*
 dependencies.m4
 depcomp
 install-sh
 libtool
 ltmain.sh
 missing
+m4/libtool.m4
+m4/lt*.m4