Issue Summary

The iFrame macro has a few alignment options, but currently there is no option to align it to the center of a page.

Steps to Reproduce

Steps:

1. Create a new page
2. Add the iFrame macro
3. Under Align, check the available options

Expected Results

There should be a "center" option under Align.

Actual Results

There are only two options for vertical alignment (left and right), and 3 options for vertical alignment (top, middle and bottom).

Workaround

A few available options are:

1. Add a single-cell table and include the iFrame macro within it
2. Add a Layout (either "Three columns" or "Three columns with sidebars") and include the iFrame macro in the center column