Optimization for error_info<throw_function>, error_info<throw_file>, error_info<throw_line>. Refactored exception_ptr to use shared_ptr.

[SVN r48521]

test/Jamfile.v2

@@ -23,7 +23,6 @@ run cloning_test.cpp ;
 run copy_exception_test.cpp ;
 run unknown_exception_test.cpp ;
 run exception_test.cpp ;
-run boost_error_info_test.cpp ;
 run enable_error_info_test.cpp helper1.cpp ;
 run throw_exception_test.cpp helper2.cpp ;
 run errno_test.cpp ;