Chrono: inhibit variadic-macros warning.

svn path=/trunk/libs/chrono/; revision=82945
Chrono: Added BOOST_FORCEINLINE on duration,time_point constructors for TI compiler.

svn path=/trunk/boost/chrono/; revision=83509
Chrono: avoid memory leak.

svn path=/trunk/boost/chrono/; revision=83510
Chrono: Added thread-safe doc for now().

svn path=/trunk/libs/chrono/; revision=83511