Fix for bug in Griddle v0.2.2

Caused layout breakage in latest webkit builds due to changes in browser handling of inline-block. More info: https://github.com/necolas/griddle/issues/16

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5439 2fea6a4d-a838-0410-917b-93a53c48e9d2