When creating/modifying a dashboard the user should be able to see at least an outline of the new column once the Add column button is clicked

Steps to reproduce:

1. Log in as Admin
2. Click on Profile
3. Click on My dashboard
4. Set Replace the default dashboard with my custom dashboard to Yes
5. Add a Gadget
6. Click on Add column (observe the UI)
7. Click on the gadget and drag and drop it to the newly created column

Expected results: When "Add column" is clicked the user can see a box or a contour/dotted box for a better visual experience.

Actual results: When "Add column" is clicked a new column is added but the UI doesn't show that to the user. The user needs to drag and drop a gadget to see the new column/box. This is a bit confusing for a user, as when you click, your first impression is that it's not working/not doing anything.

NOTE: Same thing happens when you modify the default Dashboard.