Export unsave-bug-report. Fix doc typo.

pkgs/drracket-pkgs/drracket/help/bug-report.rkt

@@ -15,6 +15,7 @@
 (provide help-desk:report-bug
          (struct-out brinfo)
          saved-bug-report-titles/ids
+         unsave-bug-report
          discard-all-saved-bug-reports)
 
 (define (bug-server-url path)

pkgs/drracket-pkgs/drracket/help/bug-report.scrbl

@@ -13,7 +13,7 @@
                                 (make-mixin-contract frame%)
                                 values])
          void?]{
-  Opens a bug report window to edit the but report identified by @racket[this-bug-id].
+  Opens a bug report window to edit the bug report identified by @racket[this-bug-id].
   If @racket[this-bug-id] is @racket[#f], then creates a new bug ID and uses that one.
   
   The @racket[frame-mixin] argument is passed the frame class before creating the window.
@@ -28,6 +28,10 @@
   open in frames.
 }
 
+@defproc[(unsave-bug-report [bug-id exact-positive-integer?]) void?]{
+  Deletes the saved bug report identified by @racket[bug-id].
+}
+
 @defstruct[brinfo ([title label-string?]
                    [id number?]) #:transparent]{
   A record representing a saved bug report. The @racket[id] field is suitable