BScrollBar: style fixes, update copyright header
BView: style fixes related to mouse scrolling
BScrollView: Increase small scroll step size from 1 to 3

... and then don't multiply by 3 in BView
WebPositive: style fixes related to scrolling

rename dy to deltaY
ShowImage: Style fixes related to scrolling
BView: Check scroll delta isn't 0
BView: ScrollWithMouseWheelDelta return status code
BView: scroll horizontally when holding control

... instead of vertically. This actually swaps horizontal and vertical
so if you have a mouse with a fancy 2-axis scroll ball it will swap
the x and y coordinates. (untested)
ShowImage: Scroll horizontally with control

...instead of command.

See http://www.freelists.org/post/haiku-commits/haiku-hrev46304-srckitsinterface,18