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 :^)
Previously we would draw all text, no matter what font type, as
Liberation Serif, which results in things like ugly character spacing.
We now have partial support for drawing Type 1 glyphs, which are part of
a PostScript font program. We completely ignore hinting for now, which
results in ugly looking characters at low resolutions, but gain support
for a large number of typefaces, including most of the default fonts
used in TeX.
When looking up differences in the specified encoding, we previously
didn't recognize a lot of characters, namely those that are referred to
by a string in the PDF itself, like "/germandbls".
We now create a mapping of those characters to the code points they are
referring to, and correctly look them up when needed.
