variable step size for value sliders

At the moment you have two additional options to control the size a value increases/decreases when sliding a value slider. Shift makes the value change in smaller increments for better accuracy, ctrl moves in bigger increments.

This is frequently an insufficient amount of control, and regularly makes the sliders unusable if the smallest step size is still too large.

I suggest that the sliders behaviour is changed so that it matches the behaviour of the 3d viewport, so that instead of clicking and keeping the mouse button held down and then dragging, the user would instead click anywhere on the property's textbox to give it focus (as if ready for typing), but then move the mouse away from the textbox and then click drag to change the value. The further away from the textbox the pointer is when dragging begins, the smaller the increment (same as when scaling in the viewport for example).

To make it easier to gauge how far to move the mouse from the textbox before click dragging, the increment value should be shown beside the mouse pointer (or in replacement for the mouse pointer).