[plt-dev] Release Announcement for v4.1.5, third call

The release announcement sketch that I have so far is below.  I didn't
get any additional edits.

Specific people:

* Stevie: Unit contracts, region contract, etc -- this should
  definitely be blurbed

* Robby: are there any Redex news?

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* Web Server:
  - new URL-based dispatching library `web-server/dispatch',
  - customizable continuation serialization policies for the stateless
    web language `web-server/stuffers',
  - abstraction of serve/servlet to build simpler dispatchers
    `web-server/servlet-env',
  - HTTP Digest authentication support `web-server/http/digest-auth',
  - built-in cookie support in `web-server/http/cookie' and
    `web-server/http/cookie-parse',
  - highlighting and pretty-printing of errors in Xexpr constructions,
  - load control dispatcher for limit concurrent sessions
    `web-server/dispatchers/limit'.

* Scribble:
  - Literate programming is now available using the new
    `scribble/lp' language.
  - A new `at-exp' language makes it convenient to use the
    scribble reader's @-expressions for general code.
  - The `scribble/text' preprocessor language has been extended to
    deal with indentation and other formatting issues.
  - The "scribble" command-line tool accepts a `--pdf' flag to
    render PDFs (via pdflatex).

* DrScheme now provides feedback when PLaneT downloads and
  installs new packages.

* Language levels and teachpacks from the DeinProgramm project for
  the German textbook "Die Macht der Abstraktion" by Herbert
  Klaeren and Michael Sperber have been added.

* Misc:
  - Typed Scheme now comes with several more pre-wrapped
    libraries, found in the `typed' collection.
  - The `xml' and `html' collections are now contracted.
  - Binding parsing in net/cgi now interacts with `net/uri-codec's
    configuration parameters.
  - DrScheme captures logging output.
  - Check syntax: it is now possible to tack arrows crossing the
    currently selected text.
  - SRFI collections are available with R6RS-frienly names as in
    SRFI-97.
  - New `bitwise-bit-field' function.

* The usual pile of bugfixes.  (Notable: `scheme/package' works,
  `deflate' compression fixed, DrScheme language dialog issue
  resolved, `match' fixes, Windows networking, and much more.)

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-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!