Since the timerbar warning can't be fixed, this should fix the remaining parts of Mantis #2829 by escaping things it confused with xml tags.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@9618 387891d4-d844-0410-90c0-e4c51a9137d3
Fix use of magic numbers in ConditionedHook::ConditionsValid()

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@9619 387891d4-d844-0410-90c0-e4c51a9137d3