#258 ":figwidth: image" generates unitless width value

[Takeshi KOMIYA]

I give ":figwidth: image" option to figure directive,
but it generates incorrect CSS styles.
the width style does not have any units.

Input:

.. figure:: logo.jpg
   :figwidth: image

   caption

Output:

<div class="figure" style="width: 448">

Environment:

• docutils-0.11
• Google Chrome

[Günter Milde]

Fixed in the repository. Thanks for the report.