Change how redraw timer is fired to be more consistently paced during cursor movement
Move lineDrawingMode flags into C array for speed
Don't call terminal on every append to get wrap and ansi flags. Instead, cache them in VT100Screen.
Cache insert mode in VT100Screen
Simplify dirty char tracking to keep a range per line
Fix busted logic in dirty chars as range and add tests
Cache append to scrollback with status bar flag in VT100Screen
Optimize reading from the socket