Support rel=0 option

Problem/Motivation

We had a need to enable rel=0 on YouTube videos. Rather than reinventing the wheel, it seemed sensible to add the option to this module. Patch is against 2.x branch. Please let me know what you think.

Steps to reproduce

Proposed resolution

Add additional "Disable related videos" option to field formatter. If enabled, add "rel=0" to the iframe src querystring.

Remaining tasks

User interface changes

New checkbox option added to field formatter.

API changes

Data model changes