Plugin compatibility with Bootstrap 3

Thanks for the great plugin. I experienced a strange issue when it comes to nested sorting and using the bootstrap grid system.

I attached a simple example here: http://s17326667.onlinehome-server.info/sortable/example.html

I want the user to be able to nest like this:

1.0 row
1.1 column
1.1.1 row
1.1.1.1 column
and so on…

When I use the bootstrap row and column classes this doesn't work after the second depth layer. It seems to have something to do with the "position: relative" property in the column class.

I wonder if this is a glitch with the plugin or the bootstrap framework. Can you shine some light on this?

Thanks,
Florian