Add more generated files to .gitignore

.gitignore

+configure.log
+cduce
 *.o
 *.cmo
 *.cdo
@@ -5,4 +7,6 @@
 *.cmi
 *.cmx
 *.cmxa
-*.a
\ No newline at end of file
+*.a
+Makefile.conf
+