Completed issue 37 - add 'at' to MainListViewActivity's head comment items
Removed redundant strings from head_comment_list_item.xml
Removed hardcoded strings from head_comment_list_item.xml
Fixed warnings in head_comment_list_item.xml
Fixed up testDisplayCommentInList in MainListViewActivityTests
Started implementing sort by date in MainListViewActivity
Implemented sorting algorithm and applied it to sort by date
Created sort by pictures algorithm
Implemented sort by pictures and date
Added comments to sort by pictures