Between the Ashes HPC request: allow ships to attack others on the same team

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@11094 387891d4-d844-0410-90c0-e4c51a9137d3
MageKing17's patch for Mantis #3110: Message Brackets not displayed with 'Invisible to Friendlies' flag

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@11095 387891d4-d844-0410-90c0-e4c51a9137d3