Adding an OSKPhotoSharingContentItem to the contentItem returned in cont...

2 Changes in this Pull Request:
1. Adding an OSKPhotoSharingContentItem to the contentItem returned in contentFromImages because, well, doing photo sharing should have photos!
2. In OSKTwitterUtility, adding a cached check to the Twitter configuration API so that we can adaptively downscale images to fit under the image size limit imposed by Twitter.