Made $Shield Impact Explosion Radius default to the value of $Impact Explosion Radius.

git-svn-id: svn://svn.icculus.org/fs2open/branches/zookeeper@10421 387891d4-d844-0410-90c0-e4c51a9137d3
Added ai_profiles.tbl options to force AI ships flying bay paths to gradually accelerate/decelerate instead of flying the path at max speed.

git-svn-id: svn://svn.icculus.org/fs2open/branches/zookeeper@10422 387891d4-d844-0410-90c0-e4c51a9137d3