Fixes crash in the texture replacement editor: Erasing the end element of a size 0 vector is probably not a safe thing to do

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10717 387891d4-d844-0410-90c0-e4c51a9137d3
restore a strcpy that was accidentally removed in r2768 (fixes Mantis #3046)

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10718 387891d4-d844-0410-90c0-e4c51a9137d3
Removing dead and potentially confusing code


git-svn-id: svn://svn.icculus.org/fs2open/trunk@10719 387891d4-d844-0410-90c0-e4c51a9137d3