mu4e-view.el: Add "scroll backwards" binding in view

[GoogleCodeExporter]

    mu4e view mode was missing a key to scroll backwards in email messages.
    Comparable modes like view-mode use <backspace>.

    Remove second binding of <backspace> to 'mu4e-view-mark-for-trash, which
    already exists on "d".  Replace first binding of <backspace> with
    'scroll-down.

    Modified   mu4e/mu4e-view.el
diff --git a/mu4e/mu4e-view.el b/mu4e/mu4e-view.el
index 3923252..5a8ec47 100644
--- a/mu4e/mu4e-view.el
+++ b/mu4e/mu4e-view.el
@@ -508,7 +508,7 @@ FUNC should be a function taking two arguments:
       (define-key map (kbd "<home>") 'beginning-of-buffer)
       (define-key map (kbd "<end>") 'end-of-buffer)
       (define-key map (kbd "RET") 'mu4e-scroll-up)
-      (define-key map (kbd "<backspace>") 'mu4e-scroll-up)
+      (define-key map (kbd "<backspace>") 'scroll-down)

       ;; navigation between messages
       (define-key map "p" 'mu4e-view-headers-prev)
@@ -526,7 +526,6 @@ FUNC should be a function taking two arguments:
       (define-key map "A" 'mu4e-view-attachment-action)

       ;; marking/unmarking
-      (define-key map (kbd "<backspace>") 'mu4e-view-mark-for-trash)
       (define-key map "d" 'mu4e-view-mark-for-trash)

       (define-key map (kbd "<delete>") 'mu4e-view-mark-for-delete)

Original issue reported on code.google.com by Derek.Up...@gmail.com on 14 Jan 2013 at 12:43