Deleting an annotation breaks viewing annotation on hover

[christinem]

When you delete an annotation as a TA, you can no longer hover over any annotation to see what it is, until you switch files in the codeviewer. If you attempt to add a new annotation but do not switch files, hovering over only works with the new annotations.

[yc2lee]

In case anyone else has this problem, check out the fix in 43e7d09