MATH: Fix Line2d intersection functions. Fix #682
MATH: Move the debug '<<' operators to the Math namespace.
MATH: Add a stream debug operator for Line2d.
GRIM: Fix a lua error when talking to Lupe. Fix #198
Fix typo.
GRIM: Fix Glottis animation when he hands the work order to Manny. Fix #237
DOCS: Fix typo.
GRIM: Fix music mismatch when shooting Hector.
GRIM: Fix music mixup at the end of the world. Fix #614
GRIM: Fix ActorToClean behaviour. Bump save version to 22.4.  Fix #701.

The clean buffer code needs two layers. Every actor needs its buffer,
but we also need a global one. The actors' buffers blit to the global buffer
which then gets blitted to screen.
GRIM/Smuch: Fix free/delete/delete[] mismatch.
GRIM/iMuse: If we're starting a sound which is fading out bring it back. Fix #246
GRIM: Don't push a costume if the actor has it already in the stack. Fix #483
GRIM: Fix Manny's animation when getting the card from the deck.
GRIM: Initialize Actor::_backgroundTalk.
GRIM: Don't enable lighting if we're drawing the shadow. Fix #294
GRIM: Fix actors roll.