FixedColumns - Table as content for header

tnobrega

When you place a table inside a header cell (th), the extension breaks. Debuggin I realized this happens because of the selector being used at the function: _fnEqualiseHeights. So I think the following:

...
rootOriginal = original.getElementsByTagName(nodeName)[0],
rootClone    = clone.getElementsByTagName(nodeName)[0],
...

should be replace with this:

...
rootOriginal = $(original).find("> "+nodeName).get(0),
rootClone    = $(clone).find("> "+nodeName).get(0),
...

this way it wont lookup for nested tables inside Datatables.