Add attribution logic for photos on site

[dencold]

One of the great things about hasper is the beautiful cover photo for each of your posts. Sometimes users may want to use images that are not their own and provide proper attribution (for photos that are cc licensed, for example). I'd like to set this up as an additional attribute in the post's meta data. If they'd like to provide attribution, they'd just set a field like attribution and provide a link and possibly some text that we can slurp in and provide a nice style either on the image itself, or on the bottom of the post's content.

These should be a helpful resources:

• http://foter.com/blog/how-to-attribute-creative-commons-photos/
• http://www.wikihow.com/Attribute-a-Creative-Commons-Licensed-Work