no horizontal scrolling in grid with columnsets (complex_column.html)

[kjvdbent]

The grids with columnsets in the testfile dgrid/test/complex_column.html doesn't seem to work properly. Horizontal scrolling is not working.

In Firefox (14.0.1) and Chrome (22.0.1215.0 dev) scrolling in the first grid ("A Grid with subrows (no ColumnSets)") works flawless, both horizontally end vertically.

The second grid ("A Grid with locking columns but only one subrow") shows a different behaviour.
In Firefox, both scrollbars (horizontal and vertical) are visible. When you drag the scrollbars, it works. Scrolling inside the grid (two-finger scroll) works only vertically. Horizontally, nothing happens.
In Chrome the scrollbars are hidden. Scrolling inside the grid (two-finger scroll) works only vertically. Horizontally, nothing happens.

Used the following version of dgrid: dgrid-v0.3.1-13-g632f229

[ghost]

Fixed by #326 and subsequent commits.