Add a view for the field type Dict in Studio.

In this PR is added a view for the field type Dict in Studio.
Ticket: [BLD-658](https://edx-wiki.atlassian.net/browse/BLD-658).
@cahrens , @frrrances please review.

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![screen shot 2014-02-05 at 14 08 50](https://f.cloud.github.com/assets/1247491/2089787/89b4311e-8e8b-11e3-9425-4df37de45708.png)