--toc-level no longer implies --toc.

Reason: EPUB users who don't want a visible TOC may still want
to set the TOC level for in the book navigation.

README

@@ -323,7 +323,7 @@ General writer options
 `--toc-depth=`*NUMBER*
 :   Specify the number of section levels to include in the table
     of contents.  The default is 3 (which means that level 1, 2, and 3
-    headers will be listed in the contents).  Implies `--toc`.
+    headers will be listed in the contents).
 
 `--no-highlight`
 :   Disables syntax highlighting for code blocks and inlines, even when

pandoc.hs

@@ -360,8 +360,7 @@ options =
                   (\arg opt -> do
                       case safeRead arg of
                            Just t | t >= 1 && t <= 6 ->
-                                    return opt { optTOCDepth = t,
-                                                 optTableOfContents = True }
+                                    return opt { optTOCDepth = t }
                            _      -> err 57 $
                                     "TOC level must be a number between 1 and 6")
                  "NUMBER")