follow-up to r10734: in the event of any SND_F flags being added in the future, this is more future-proof

git-svn-id: svn://svn.icculus.org/fs2open@10742 387891d4-d844-0410-90c0-e4c51a9137d3
roll back r10741 pending further code review; see Mantis #3052

git-svn-id: svn://svn.icculus.org/fs2open@10743 387891d4-d844-0410-90c0-e4c51a9137d3
better variable name

git-svn-id: svn://svn.icculus.org/fs2open@10744 387891d4-d844-0410-90c0-e4c51a9137d3
code reuse is A-1 SUPAR

git-svn-id: svn://svn.icculus.org/fs2open@10745 387891d4-d844-0410-90c0-e4c51a9137d3
get the user.home path in a way that works on all platforms (bypass a Java bug that occasionally had user.home return the wrong location on Windows)

git-svn-id: svn://svn.icculus.org/fs2open@10746 387891d4-d844-0410-90c0-e4c51a9137d3
well, this is no longer needed

git-svn-id: svn://svn.icculus.org/fs2open@10747 387891d4-d844-0410-90c0-e4c51a9137d3
fix a bug in the when-argument sexp that managed to escape detection from its original design!
spotted by MageKing17, fixes Mantis #3052

git-svn-id: svn://svn.icculus.org/fs2open@10748 387891d4-d844-0410-90c0-e4c51a9137d3