Add `shadow' face and move `mode-line-highlight' to new section `New faces'.

etc/NEWS

@@ -798,6 +798,21 @@ appears in.
 *** The variable `cursor-in-non-selected-windows' can now be set to any
 of the recognized cursor types.
+** New faces:
+
++++
+*** `mode-line-highlight' is the standard face indicating mouse sensitive
+elements on mode-line (and header-line) like `highlight' face on text
+areas.
+
++++
+*** `shadow' face defines the appearance of the "shadowed" text, i.e.
+the text which should be less noticeable than the surrounding text.
+This can be achieved by using shades of grey in contrast with either
+black or white default foreground color.  This generic shadow face
+allows customization of the appearance of shadowed text in one place,
+so package-specific faces can inherit from it.
+
 ** Font-Lock changes:
 +++
@@ -4797,9 +4812,6 @@ line.
 +++
 *** Mouse-face on mode-line (and header-line) is now supported.
-`mode-line-highlight' is the standard face indicating mouse sensitive
-elements on mode-line (and header-line) like `highlight' face on text
-areas.
 ** Menu manipulation changes: