Remove shared libraries as part of "make clean" rather than in "make
clobber".  This is done so that after a "make clean", setup.py will
also recompile all extensions.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 2686ad5..f81702b 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -751,11 +751,12 @@
 
 clean:
 	find . -name '*.o' -exec rm -f {} ';'
+	find . -name '*.s[ol]' -exec rm -f {} ';'
 	find $(srcdir) -name '*.py[co]' -exec rm -f {} ';'
 
 clobber: clean
 	-rm -f $(PYTHON) $(PGEN) $(LIBRARY) $(LDLIBRARY) $(DLLLIBRARY) \
-		Modules/*.so Modules/*.sl tags TAGS \
+		tags TAGS \
 		config.cache config.log config.h Modules/config.c 
 	-rm -rf build