Pull in an updated x11-canvas-screencast submodule.
Update the animations.

 * Make the click-on-symbol animation shorter and split the #include file
   clicking off into a second animation.

 * Split the xref animation into two xref animations, one for a field and
   one for two functions.

 * Add an animation that shows browsing BasicBlock members using the regex
   ^llvm::basicblock.

 * The first set of animations were done with LCD/subpixel font smoothing,
   and they might look bad on monitors with different subpixel arrangement
   than mine.  This set of animations uses grayscale font smoothing.

 * Show each animation just once before moving to the next animation.  If
   the user wants to see the same animation again, they can use the back
   arrow.

 * Make the animations smaller.