Add seek preset option

As mentioned here (https://www.drupal.org/node/1894656#comment-11184359), we have created a seek preset option.

Having this option will allow developers to limit seek functionality to a specific field on a page. For example, a YouTube-like page could be built where the main player allows for seeking by URL (http://mysite.com/video/uploaded-video#t=15), but all other thumbnail players and related videos do not have seek functionality.

See the attached picture for how this looks in the preset settings. We will post the patch once some of the other related patches have been committed.