Pushed some config (which will always be the same) down in to the class.
Some renaming.
What was the DownloadDataView is about to become a GridPanel, to be consistent with the FacetedSearchResultsGrid.
Download cart is now a GridPanel.
This is for consistency, as well as enabling things (e.g. removal) to be done in a more Ext-y way, and without the use of global functions.
Wrapping DownloadPanel, so that header appears.
Refactored the download grid view and column model in to own classes.
Some UI refinements.
Refactored test.
'Empty text' is now showing, added 'remove' column.