Turn timing logging on unconditionally.
Respect `typechecker:called-in-tail-position` when calling non-thunks.
Use the form name from `match*/derived` to improve error messages.
Add annotations to 2dmatch to help typecheck.

Also use `match*/derived` to get the right error message name.
Add a test for 2dmatch + Typed Racket.
Fix typo in readtables documentation
Fix typos spotted by Ambrose Bonnaire-Sergeant.
Extend heaps to allow removing arbitrary elements via an additional equality operator.
Fix of PR 14413

Improved type per Ryans suggestion.
Refactor TR `define` to avoid a performance bug

After commit 3d177e454ea3634060a4b9b0814f588bc7c74e49
running the main `math.scrbl` file would show peak memory
usage of around 600-700MB when before it was around 400MB.

The proximal cause appears to be the expansion of TR
definitions, which added an extra `begin` in some cases,
combined with redefinitions at the top-level. I don't
know the core cause yet.

Thanks to Matthew for pointing out the issue and to
Vincent for helping with debugging.
add some error checking for when reading in the content of files
Real fix for the issue in the math docs

Commit 92b0e86ed1cf0270730c004211387b3fdc4b0469 turns
out to have been the wrong approach, because there was no mysterious
performance problem with TR. Instead, TR's `define` expanded to new
code that interacted poorly with a macro used in the math docs.

I've kept the refactoring from that commit because I think it still
makes the code clearer, but I've removed the now extraneous comment.
Checkpoint
Replaced plot's 3D depth sort hack with a BSP tree

The following should look as expected now:

 * Intersecting or adjacent surfaces, isosurfaces, lines and paths,
   even if they're sampled at different intervals.

 * Rectangles that aren't spaced regularly on the x,y plane (e.g.
   sideways histograms; the rectangles I plot to debug Dr. Bayes).

In general, the rendering should be robust enough to draw arbitrary
3D scenes, and it still produces high-quality PDFs.

Drawing 3D plots still has the same time complexity and seems to be
about as fast as before. Thanks to the fact that sorting objects by
view distance is an O(n) BSP tree walk, rotating 3D plots in
DrRacket is probably a little faster.

This update also adds direct support for connected lines, and
includes a fix that makes contour lines easy to see, even when
plotted on top of a non-contour-interval surface. (This wasn't
possible before.) Further, the 3D plot area no longer requires a
"grid center" vertex by which to sort grid-aligned shapes, making
the rendering API friendlier, and closer to ready for public use.
fix extra message on timeouts

and division by 0 that caused null results to not save
refactor benchmark loops for clarity
Changed let-poly's unification algorithm
to be simpler and clearer

This caused bug #6's counterexample to change
because the unification algorithm no longer calls
∨ so we have to find a different way to call it
Fix TR docs for the addition of typed/racket/class
racket/gui mac os x: fix compatible-bitmap scale on slow path
fix problem with @2x bitmaps on Mac OS X 10.5