Merge branch 'v4-dev' of https://github.com/twbs/bootstrap into v4-dev

scss/mixins/_grid.scss

@@ -67,7 +67,11 @@
 }
 
 @mixin make-col($size, $columns: $grid-columns) {
-  width: percentage($size / $columns);
+  flex: 0 0 percentage($size / $columns);
+  // Add a `max-width` to ensure content within each column does not blow out
+  // the width of the column. Applies to IE10+ and Firefox. Chrome and Safari
+  // do not appear to require this.
+  max-width: percentage($size / $columns);
 }
 
 @mixin make-col-offset($size, $columns: $grid-columns) {