avoid a deadlock introduced in recent identifier highlighting commit
racket/gui: doc clarifications on refreshes and edit sequences
reference: fix typo and terminology for `with-continuation-mark'

Closes PR 13478
another close-paren insertion repair

(this one causes runtime errors, not
bad behavior)
Fix `sequence-lift` for multiple valued sequences.

Also minor fixups of the rest of `unstable/sequence`.
fix a problem with the way that check syntax's interval map
tracks information about the program
x86_64-mac: Pango CoreText repair

Closes PR 13473
fix doc mistake

Closes PR 13482
fix doc typo

Closes PR 13483
fix find-seconds error reporting to say "find-seconds" instead
of "find-secs"
change the default test coverage colors

After some consultation with my class this quarter,
it seems clear that the previous defaults and nearby
variations are completely hopeless for colorblind people
(there are at least 3 in this class). So go with the
defaults used in the HtDP languages, which have been
vetted by saidsame 3 people.
give up on the "find the close paren strategy that doesn't
edit the buffer" attempt

In other words, go back to (a rackety version of) the old
implementation of the get-close-paren method
Spelling error

Also, Rackety
adjust raco test so that it accepts multiple -s arguments on the command-line

This is, afaict, a completely backwards compatible way to add this
functionality in the sense that any of the non-error command-line
arguments passed to raco test before still do precisely the same
things
change printouts from raco test to be slightly more informative
adjust class/c to compute projections once, instead of once per
use of the resulting contract
PR 13471: Add cycle-detection during lex-abbrev expansion to raise appropriate syntax error.
Also add test cases for lex-abbrev cycle detection.
Correct the test case so it executes the error path we want.
Make generated contracts for Floats include NaN.

Closes PR13464.
Add extra tests for contract generation and float zeroes.