Can not select image when navigating text with arrow keys.

[Joe Kavanagh]

1. Add some text, insert an image, and add some more text after the image.
2. Using the left arrow key move the cursor back to select the image.

Observe that the cursor by-passes the image an moves to the text before the image. This prevents the user from opening the image context menu using the keyboard.

[Joe Kavanagh]

This is also occurring for flash objects.

[Frederico Caldeira Knabben]

This may be a browser limitation. We need to check if it's possible to workaround it.

[Garry Yao]

@fred That's exactly what been proposed these days at Mozilla.
​https://wiki.mozilla.org/Accessibility/EditorBehaviourOnUserInput

[Garry Yao]

It's definitely a browser bug, and has appearance on both IE and Firefox (works with Webkit for me right now).
Even worse, this phenomenon happens to every type of control ( checkbox, img, select) in condition that the element is surrounded by text. Most unfortunately, due to #703 and #3069, what been impacted is that SHIFT+ARROW keys/mouse drag will be the only way for selecting such elements in FF3.
Considering the wide affecting of this bug, I'm proposing an fall-back range inspection approach to selection.getSelectedElement to correctly figure out the element underhood.
Then we'll be sitting and looking for the real fix at the browser side.