arbitrary point. It has been replaced with a variant that takes a polyobject
as a source, since that was the only use that couldn't be rewritten with the
other variants. This also fixes the bug that polyobject sounds were not
successfully saved and caused a crash when reloading the game. Note that
this is a significant change to how equality of sound sources is determined,
so some things may not behave quite the same as before. (Which would be a
bug, but hopefully everything still sounds the same.)
SVN r1059 (trunk)
