Begin layout for Command Explorer in Dashboard UI

- Command Explorer
  - Screenshot: http://i.imgur.com/oNQznrQ.png
  - Add all elements for first draft of Command Explorer except Command
    Options for specific commands (those will be some sort of custom
    widgets).
- Commit Explorer
  - Screenshot: http://i.imgur.com/CZTLTm2.png
  - Add text "hints" for Author and Committer fields in Commit Details