Raised version to 3.0.2 in config.h

Told the Makefile not to panic if creating /usr/include due to it existing
(due to bin not being allowed to create it) fails, this smoothens installs
done by bin (instead of root).

include/Makefile

@@ -7,5 +7,5 @@ clean::
 
 install::
 	-rm -rf $(INC)
-	mkdir $(INC)
+	mkdir -p $(INC)
 	tar cf - `find . -name '*.h'` | (cd $(INC) && tar xf -)