[Boost-users] serialization library has misspelled constant

The struct boost::serialization::tracking_level has a misspelled constant. Instead of it having a constant named "track_selectively", the constant is misspelled "track_selectivly". For backward compatibility, I would add a new constant with the correct spelling that has the value of the old, misspelled constant. (This bug exists in v. 1.33.1 of boost.) --Dan.