Fix mantis 2804: beams can use damage factors

Add game_setting.tbl option that allows beams to use weapons table
Armor/Shield/Subsystem damage factors

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@11089 387891d4-d844-0410-90c0-e4c51a9137d3