We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Turns out most things expect lines to include the endpoint,
e.g. 0,0 -> 3,0 is a 4px long line. But the fill_path() implementation
seems to expect the line to be the distance between the two points
(so the above example is a 3px line instead).
This now adds an option to pick between PointToPoint line length or
Distance line length and uses the latter for fill_path().
draw_line_for_path() is the same as the standard antialiased
draw_line() but with a few few small hacks to improve the look of
paths.
AntiAliasPolicy is also removed as it's now unused.
