Adding multiple groupings with resizeableRows causes renderRow to fail

[thomb]

If resizableRows are enabled and you attempt to add multiple groups the grid breaks in the renderRow function, specifically :8107 in the latest build.

Worth noting this only occurs when there is a partial Remote Data dataset loaded, if you load all items in the dataset multiple grouping works without issue.

[thomb]

This bug report wasn't entirely accurate. Full Reproduction steps are:

• add a column grouping
• change the column grouping
• attempt to add a 2nd column grouping

It does appear to be related to remote data sets, as I can't reproduce this on the example grid here http://dobyjs.com/#grid-options-resizableRows