tag inside them, previously it was expanded to be a caption with a single paragraph in it. Now, it's just removed and no caption is set. This is important because torus will render an extra frame around iframes with captions that throws off the intended alignment/sizing from legacy courses.
Iframes where the author has specified a size (ie. it's not the default echo iframe size) will have that size exported. In the case where the iframe is set to 800x450, the default echo size, no size is exported. The thinking is the author didn't set a size and wanted to use the default, and torus has it's own default to use.
Two changes to support sizing iframes in torus