twitter/bootstrap — pull request #4193 by thomas-mcdonald (2012-07-27 09:00:30+00:00)
Title: Move the clearfix definition out of mixins and into reset

This means that people who want to only use the Bootstrap mixins will no longer have a rule inserted into their stylesheet when importing only mixins.less.

Reset seems like the most appropriate place for it to go, although I suppose utilities would also be a valid location.

See also thomas-mcdonald/bootstrap-sass#166