[boost] Added "restore" member functions to ios_state

See "BOOST_ROOT/boost/io/ios_state.hpp," CVS version 1.3, and "BOOST_ROOT/libs/io/doc/ios_state.html," CVS version 1.7, if they uploaded OK. (I had a temporary[?] wait on my own lock.) -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com