Fix EZP-22685: Embed images displayed side-by-side in Online Editor

JIRA: https://jira.ez.no/browse/EZP-22685

# Description

In Online Editor, if you add some images, they are always aligned side by side even if they are not configured to *inline*.

This patch makes sure the images are aligned depending on the inline parameter so that the editor has a better preview of how the page will be rendered.

![image-ezoe](https://cloud.githubusercontent.com/assets/305563/2942987/c1fcf34a-d9bc-11e3-93cf-fba23fa18c9f.png)

# Tests

manual tests