Changing then blurring text block causes refocus

[aduth]

Raised at #360 (comment)

Steps to reproduce:

1. Focus a text block
2. Change the content
3. Click outside the editor

Expected result:

The block becomes unfocused.

Actual result:

The block remains focused.

Expected cause:

The visual editor block wrapper is receiving a focus event after blurring. It's uncertain where this event originates. Perhaps TinyMCE? Suspicious that it only occurs after a change has been made.

[aduth]

No longer able to reproduce this issue.