Set max-age header to Amazon S3 resources
If post has photos, always include url in post to Facebook to stay consistant with other servies, fixes #3706
Merge pull request #4052 from jaywink/3706-facebook-missing-link

If post has photos, always include url in post to Facebook
Merge pull request #4048 from marpo60/s3_max_age

Set max-age header to Amazon S3 resources