Coverity ID 1093508: Negative array index write in observer_create()

git-svn-id: svn://svn.icculus.org/fs2open@10214 387891d4-d844-0410-90c0-e4c51a9137d3
Coverity ID 1093550: Negative array index write in multi_voice_release_token()

git-svn-id: svn://svn.icculus.org/fs2open@10215 387891d4-d844-0410-90c0-e4c51a9137d3
Coverity ID 1093808: Uninitialized scalar variable in init_ai_target_priorities()

git-svn-id: svn://svn.icculus.org/fs2open@10216 387891d4-d844-0410-90c0-e4c51a9137d3
Coverity ID 109381[456]: Uninitialized scalar variable in load_gauge_target_monitor()

git-svn-id: svn://svn.icculus.org/fs2open@10217 387891d4-d844-0410-90c0-e4c51a9137d3
Coverity 110733[01]: Negative array index read in get_string_or_variable()

git-svn-id: svn://svn.icculus.org/fs2open@10218 387891d4-d844-0410-90c0-e4c51a9137d3