run update whatsnew

docs/source/whatsnew/development.rst

@@ -1,23 +1,37 b''
 =====================
  Development version
 =====================
 
 This document describes in-flight development work.
 
 .. warning::
 
     Please do not edit this file by hand (doing so will likely cause merge
     conflicts for other Pull Requests). Instead, create a new file in the
     `docs/source/whatsnew/pr` folder
 
 
+Added a ``Valid`` widget which inherits the ``_Bool`` widget and displays a green checkmark or red cross depending on the truth of ``.value``.
+
+Callbacks registered with the ``Widget.on_some_change`` method are passed the Backbone model ``change`` event's arguments.
+
+The serialization of widget traitlets can be customized.  Custom serialization can use binary message buffers.  Refer to :ghpull:`7757` for more information.
+
+Code raising ``DeprecationWarning``
+entered by the user in an interactive session will now display the warning by
+default. See :ghpull:`8480` an :ghissue:`8478`.
+
+The `--deep-reload` flag and the corresponding options to inject `dreload` or
+`reload` into the interactive namespace have been deprecated, and will be
+removed in future versions. You should now explicitly import `reload` from
+`IPython.lib.deepreload` to use it.
+
 .. DO NOT EDIT THIS LINE BEFORE RELEASE. FEATURE INSERTION POINT.
 
 
 Backwards incompatible changes
 ------------------------------
 
 
 .. DO NOT EDIT THIS LINE BEFORE RELEASE. INCOMPAT INSERTION POINT.
 
-