BView: Style fixes only, no functional change intended

Motivated by inconsistancies found while documenting BView.

Update copyright year, alphabetize

Variable names normalized:
* pt => point
* r => rect
* p => pattern
* c => color
* msg => message
* a, b and pt0, pt1 => start, end
* r, g, b, a => red, green, blue, alpha

A couple of white spaces fixes.

A couple of !pointer => pointer == NULL fixes.

GetPreferredSize params => _width and _height to indicate out params.
Update BView docs for changes in hrev45799
BView docs: Add remaining new method descriptions

Layout and Tool Tip method documentation.

Also ScrollWithMouseWheelDelta()