[boost] [system][test] system_error

Folks, We currently have two classes named "system_error": boost::system_error in Boost.Test and, boost::system::system_error in Boost.System. IMO the first of these probably shouldn't be there: either it should be moved to a sub-namespace, or else should be using Boost.System. Thoughts? Cheers, John Maddock. PS, I'm still seeing regex failures as a result of Boost.Test throwing system_error's.