Implemented mouse-wheel scrolling.
More TODOs.
Numbered each of the sample items.
Added click to select items. Also finished the implementation of WM_SETFONT.
Implemented focus coloring and redrawing.
Added keyboard selection changes.
Started writing the new Table's header.
More TODOs.
Tried to set up the viewport for the header area. Drawing still not done.
More header bar stuff.
Undid all the scrolling muckery. Going to need to figure this out for real...
Reimplemented header scrolling.
Fixed click to select for the header bar.
Implemented text cell drawing.
Implemented live column size changing.
Removed a bunch of flicker from header resizing.