laravel/framework — pull request #4366 by RyanNielson (2014-05-08 15:45:25+00:00)
Title: Add disassociate method to belongsTo

Added this based on suggestions by @daninoz in #4350. There may be a better way to do this, but I whipped it up quickly and based it off of how associate() currently works.

Put it in 4.1 as it shouldn't cause any backwards compatibility issues.