Copy images for inlinemediaobject

[lcawl]

Related to #541

If I use an inline image, it's not being copied to the output directory (thus resulting in a broken image).

For example, if I have a block image followed by an inline image:

image::xpack-tag.png[X-Pack]

image:test-star.png[Star]

It generates:

<div class="informalfigure"><div class="mediaobject"><img src="xpack-tag.png" alt="X-Pack" /></div></div><p><span class="inlinemediaobject"><img src="test-star.png" alt="Star" /></span></p>

But only the first file is copied to the output directory: