runqueue.py: Add bb.runqueue.check_stamp_fn() for use by packaged-staging, also impro...

[vuplus_bitbake] / TODO

On popular request by popular people a list of tasks to-do:

        -Kill insecure usage of os.system either by properly escaping
         the strings or a faster replacement not involving /bin/sh
        -Introduce a -p option to automatically hotshot/profile the
         run