[boost] [flyweight] rw_locking policy patch for review

i have implemented a rw_locking policy for flyweight factories, based on boost::shared_mutex. to achieve that, i had to adapt the factory interface ... joaquín, would it be possible for you to review the patch? it is based against the version of flyweight from the boost sandbox svn ... best, tim -- tim@klingt.org http://tim.klingt.org Cheat your landlord if you can and must, but do not try to shortchange the Muse. It cannot be done. You can't fake quality any more than you can fake a good meal. William S. Burroughs