[racket-dev] Release Announcement for v5.3.4

The release announcement sketch that I have so far is below.  Please
mail me new items and/or edits.
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mflatt:
  - added file-truncate (48e05093)
  - mach-o: handle some new load commands (a229f292)
  - mach-o: code signing fixes (1744a787)
  - scribble/latex-properties: add command-extras (17865bfa)
  - ffi/com: improve handling of type-described (79266fcf)
  - added scribble/book and scribble/report langs (09d4aa3d)
  - add _size, _ssize, _ptrdiff, etc (d46411d3)
  - add phaseless modules (899a3279)
  - improve complexity of hash-iterate-{key-value} (7a8c2ff0)
  - add 'so-mode to system-type (cdf0f6b9)
  - add interactive to slideshow (454f4c3f)
  - ffi/com repairs, including mysterx compat (6e40caa7)

robby:
  - added union-find (33747ec9)
  - 2d (bb216d14)
  - improved jump-to-def (39e4ac15)

jay:
  - various pkg (39ae7a83, 9d3a42f1, 6bf03c12)

dyoo:
  - parser-tools (9e0fce22, ???)
  - fixed readline (f1e70516)

eli:
  - add links to old documentation (250880d2)
  - add {take,drop}f, splitf-at, etc (bb17b6a8, 2cdfe18b, 3af72eca)
  - make configure install docs in standard place (59b18eec)

ryanc:
  - added #:datum-literals (d5fe6021)
  - added unstable/macro-testing (1ef38458)
  - added unstable/socket (b3afbdd4)
  - added #:grammar to defform, etc (293b208a)

sstrickl:
  - with-contract improvements (539c25bb)

chrdimo:
  - support for multiple blame parties (17e419e7)
  - added option contracts (5808b0c4)

bfetscher:
  - redex-generator: determine bound order automatically (2a9d4221)

stamourv:
  - move optimization coach to planet2 (2c8e5f9a)

asumu:
  - make srfi/19 compat with date* (d406e2db)
  - separate in/out contracts for parameters (3ddde6a7)

Michael Filonenko:
  - extflonums (17b80926)
  - extflounum unboxing (840fc9c6)

Eric Dobson:
  - AnyValues type (aac25b42)

Tobias Hamer:
  - readline improvements (0f6a5833)
  - support multiple values in wrap-evt and handle-evt (7e2b443f)

Patrick Mahoney:
  - move eopl language to racket (b265e260)

Chris Jester-Young:
  - fix srfi/61 use of =>, else (9e93ee26)

Juan Francisco Cantero Hurtado:
  - fix configure for openbsd (292c81a8)

William Bowman:
  - changed define-union-language to merge nts (b0db8798, 42847ea5)

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