fix collapse.js IE8  bug
Merge pull request #16 from ixisio/master

[Patch] '$.support.transition.end' is null or not an object (IE8)
Show and Hide events instead of adding click event to dropdown
Merge pull request #17 from mpnkhan/master

Show and Hide events instead of adding click event to dropdown Fixes #13
Merge branch 'master' into gh-pages