Closes #108. Show the proper accessoryType for shared URLs.

Properly show the correct accessoryType for TTNavigationModeShare
navigation modes. We only show the right arrow for Create and Share
modes, as Modal and External do not result in the correctly implied
animation.

src/TTTableItemCell.m

@@ -71,7 +71,8 @@ - (void)setObject:(id)object {
                                          navigationModeForURL:item.URL];
       if (item.accessoryURL) {
         self.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
-      } else if (navigationMode == TTNavigationModeCreate) {
+      } else if (navigationMode == TTNavigationModeCreate ||
+                 navigationMode == TTNavigationModeShare) {
         self.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
       } else {
         self.accessoryType = UITableViewCellAccessoryNone;