Select entire columns/rows in a way that's easier for the user to remember

[Robert Leach]

Right now, to select entire rows or entire columns, there are different modifier keys associated with clicking & dragging the mouse. Which modifier to use to select rows versus columns might be difficult for the user to remember. There might be a more intuitive way to implement whole column/row selection.

1. One possibility is a single modifier key in combination with drag direction (horizontal drag would select columns, vertical - rows). It could update on the fly, so if they start horizontal, then go vertical, it could switch.
2. Another is the ability to resize the borders of the selected area by click & drag the same way you edit a selected area in an image editor.
3. The shift key (or some other key) could toggle between 3 states: a selected square of spots, their columns, or their rows.
4. Clicking & dragging in the label area (order click one column, then shift-click another column to select it and the intervening columns).

1 or more of these methods might be desirable.

[Robert Leach]

Lance suggested method #4 when we were talking about this.

[Robert Leach]

This would be affected by issue #30 if we were to implement it.

[Robert Leach]

Part of the whizzing labels branch that was merged today.

[Robert Leach]

Merged to master.