Create a directory for locking purpose
# $Header: /CVSROOT/lockdir/DESCRIPTION,v 1.1 2008-08-01 00:11:14 tino Exp $
#
# $Log: DESCRIPTION,v $
# Revision 1.1  2008-08-01 00:11:14  tino
# first commit
#

This does not create a lockfile, it creates a lockdir.
While it waits it presents you with a waiting indicator.
Returns true if successful, false otherwise.
You can give a maximum waiting time.  If this time
is reached the lockdir is removed via rmdir.
(This can fail, by purpose.)