avoid rdep in the top level make process (subdir.mk) - it leaks too much memory and increases the startup time for regular make commands. timestamp.pl is more lightweight here

SVN-Revision: 8533

Fix the annoying base-files autorebuild bug. When checking file mtimes in directories, timestamp.pl was following symlinks. This broke on base-files, because there are symlinks to /tmp and to /proc/mounts in the build directory.

SVN-Revision: 6084