make grid view background white so list view doesn't bleed through.
Changed collection view loading of "Loading More" cell so it doesn't load from lower right.

Reference to Issue #67
Removed GridView variable NSError *error and changed updateLoadingCell to updateLoadingCellWithError:
Merge pull request #314 from MIT-Mobile/3.6/news-collection-view

Refreshing loading more collection view cell text/indicator and not cell