Scrollbars should include far right/bottom pixel column/row (Fitt's Law)

[sethwoodworth]

Scrollbars, by necessity for small screens, are small in sugar. But we are not utilizing the right-most pixel as part of the scrollbar. As cited in the Sugar HIG[0] states that screen corners and edges are control interfaces that are highly usable according to Fitt's Law[1].

Here is the current interaction when someone wants to scroll down in an activity:
1. User moves cursor to the far right scrollbar.
2. User overshoots by one pixel to the right-most pixel (Y-max)
3. User clicks and drags the cursor up or down.
4. Sugar doesn't respond.

Ideally, this would happen:
1. User moves cursor to the far right scrollbar.
2. User knows and expects the Y-max to be clickable as scrollbar
3. User clicks and drags.
4. Sugar scrolls the window.

[0]  http://wiki.sugarlabs.org/go/Human_Interface_Guidelines#Activation_Methods
[1]  http://en.wikipedia.org/wiki/Fitt%27s_law

[sethwoodworth]

I was wrong. This isn't sugar-wide: it doesn't effect Journal or Help, but does effect Terminal. I will now log which activities this effects and which it doesn't so this bug can be reassigned.

Does:
* Terminal
* Abiword

Does Not:
* Journal
* Help
* Chat

Not relevant:
* Moon