issue/1760-reader-comment-full-images

Fix #1760 - images in comments are now shown full-width. The fix for the problem is a bit hacky (see [here](https://github.com/wordpress-mobile/WordPress-Android/pull/1781/files#diff-05d103d640d086958f8553f7bc491c2eR106)) but appears to work reliably.
I thought `view.requestLayout(); view.invalidate();` would be sufficient but that doesn't work: