Remove gcc warnings (unused)

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10548 387891d4-d844-0410-90c0-e4c51a9137d3
Fix for an invalid index crash.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10550 387891d4-d844-0410-90c0-e4c51a9137d3
Fix for Mantis 3027: Crash if ship AI is forced to change target

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10552 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Mantis 3029: Clang warning: expression result unused in multi_pinfo_blit_squadron_logo()

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10556 387891d4-d844-0410-90c0-e4c51a9137d3
Fix issue 3030: Clang warning: semantic issue, '&&' within '||' in gr_[re|un]size_screen_pos() and gr_[re|un]size_screen_posf()

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10557 387891d4-d844-0410-90c0-e4c51a9137d3
Project files in Xcode4 folder adopt latest suggested project file settings from Xcode 5.1.1

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10558 387891d4-d844-0410-90c0-e4c51a9137d3