Meta Line Out Of Listing

Line number inside <meta/> in XMIR cannot be bigger than amount of lines in the listing.

Incorrect:

<program>
  <listing>first line
    second line
    third line</listing>
  <metas>
    <meta line="500">
      <head>hello</head>
      <tail/>
    </meta>
  </metas>
</program>

Correct:

<program>
  <listing>first line
    second line
    third line</listing>
  <metas>
    <meta line="2">
      <head>hello</head>
      <tail/>
    </meta>
  </metas>
</program>