Created by: pelme
Currently, .collapse.in specifies overflow: hidden, probably to make the animations behave correctly.
This causes problems when using drop-downs or other dynamic content that overflows the collapse area.
This can be seen in this jsfiddle: http://jsfiddle.net/rdXfZ/1/
The commit simply uses overflow: visible for .collapse.in, and patches the show/hide in collapse() to properly set overflow.