Horizontal scrolling key change

It’s been brought to my attention that we’ve been using the wrong modifier key to get horizontal scrolling with the mouse wheel. In particular, we have it as Ctrl, but every platform I’ve checked has it as Shift. Is it going to bother anyone if we change it to Shift for 3.2.12?

Please change it.

Thus spake bdgza:

Please change it.

Done. Committed to trunk@9063.