Addresses the following UI issues:
* Increases the size of the blocks editor iframe.
* Removes the '(Debugging)' tab, which is shown now only when a bug occurs
-- Click on the 'bug' tab to simulate an exception
* Adds an about Tab which contains version number and links to release notes
* Removes 'Design' tab.  Designer is opened from Projects View by clicking on project name.
* Moves the 'Download all' button within the 'More Actions' menu.
* Adds a 'Confirm' dialog to the 'Download all' action.

5/5: Finalized color and position of TopPanel buttons.

Change-Id: I342bc2338c73bed801ed35781c966dfbb2295eb0