Fixes #7213 Collapse plugin does not correctly set the "collapsed" class.

[sody]

Collapse plugin does not correctly set the "collapsed" class on accordion heading links.
Patch includes fix and tests.

Before:
http://jsfiddle.net/uzSJD/6/

After:
http://jsfiddle.net/uzSJD/5/

[Hedde]

+1

[cvrebert]

Competing PR that also claims to fix #7213: #7243

[intellix]

This doesn't work programmatically:

$('#body2').collapse('toggle');
$('#body2').collapse('hide');
$('#body2').collapse('show');

The arrows don't change through this. Shouldn't they be connected?

[fat]

cool - thanks for the tests

[vyruz1986]

What about @intellix 's comment about the programatic toggling? In bootstrap 3.2.0 this doesn't seem to be working: http://jsfiddle.net/6f6g536r/2/

[hnrch02]

@vyruz1986 See #13636.