Dimensions on images outside document root directory:
  input: |
    !10x10.gif! in test directory

    !../textile-wordmark.png! exists in php-textile root directory, but dimension read is prevented

    !../../10x10.gif! above root directory, access prevented
  expect: |
    <p><img alt="" src="10x10.gif" /> in test directory</p>

    <p><img alt="" src="../textile-wordmark.png" /> exists in php-textile root directory, but dimension read is prevented</p>

    <p><img alt="" src="../../10x10.gif" /> above root directory, access prevented</p>