Bugfix on expanding last row of a grouped view

[pigiax]

When you have a grouped view, and expanding the last one there are 2 problems: 1) The last row expander style is not changed 2) Expanding another row, will duplicate the last one

[csigrist]

Thanks so much for fixing this. I hope it gets rolled into the master branch soon.

[icoxfog417]

It may be fixed by Pull #898 also.

It is not merged to master branch, but I already merged to my fork. https://github.com/icoxfog417/SlickGrid/tree/mergeFix

[6pac]

An equivalent patch has been integrated into my 'alternative master'. Any testing is appreciated. See https://github.com/mleibman/SlickGrid/issues/1055