To server administrators....

If you are UPGRADING from a previous version, open up the server.cfg included in the text file.  Wherever there is a piece indicating that a selection is NEW, modify your servers server.cfg to include the said line.  While NOT having the line will usually not make adverse affects, it will make it difficult to modify those settings later.  Thanks.

For 1.6, "real_ball_flight" has been added.