[boost] [thread rewite]

Matt, Anthony, You are making any changes to the thread library on a cvs branch right? We aim to keep the cvs HEAD in as close to a release-ready state as we can, so new / experimental code shouldn't be in the HEAD right now. I'm asking because we already have some regressions caused by changes to call_once in the cvs HEAD: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/thread.... Thanks, John.