update HISTORY based on some of Jay's changes

please include in 6.0

pkgs/gui-pkgs/gui-lib/mred/HISTORY.txt

@@ -11,6 +11,8 @@ Framework: changed backward-containing-sexp so it returns #f in
  more situations
 Framework: syntax colorer now usees 'text' for stuff between {}s
  in scribble mode (not string)
+bitmap-dc% get-pixel and set-pixel now transmit alpha values to/from
+ their arguments
 
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racket/collects/racket/HISTORY.txt

@@ -112,6 +112,8 @@ Libraries: ----------
  setup/collection-name: added
  pkg/path: added, re-exported by pkg/lib
  net/url: add support for HTTP/1.1 connections
+ net/url: add Host: and Content-Length: headers to HTTP requests 
+  (if they are not already included)
  xml: added a #:insert-newlines? argument to write-xexpr
  ffi/unsafe: added array-type and in-array
  ffi/unsafe/objc: add -A and +A method modes