addurl: Added --with-files option.

doc/git-annex-addurl.mdwn

@@ -75,6 +75,14 @@ be used to get better filenames.
   Enables batch mode, in which lines containing urls to add are read from
   stdin.
 
+* `--with-files`
+
+  When batch mode is enabled, makes it parse lines of the form: "$url $file"
+
+  That adds the specified url to the specified file, downloading its
+  content if the file does not yet exist; the same as
+  `git annex addurl $url --file $file`
+
 # SEE ALSO
 
 [[git-annex]](1)