Revised SVG stuff

[Werner LEMBERG]

Hello Moazin,


just now I've pushed new branches to the FreeType and FreeType Demo
repositories with my changes.

  
https://gitlab.freedesktop.org/freetype/freetype/-/tree/wl/freetype-ot-svg-from-scratch-new
  
https://gitlab.freedesktop.org/freetype/freetype-demos/-/tree/wl/freetype-demos-support-ot-svg-glyphs-new

While the library stuff is thoroughly checked and modified[*], the
demo stuff is not yet; to the latter code I've only applied the
necessary fixes to make it compile.

The reason why I've stopped is that I wasn't able to render this SVG
font:

  
https://get.fontspace.co/download/family/gep41/ffdec6d38cd94d51803685fec480ef08/bigpartyo2-green-font.zip

Funnily, it was the first SVG that I downloaded, and I was quite
surprised to see no SVG rendering at all :-)

AFAICS, the error 'Unimplemented Feature' is returned in line 502 of
file `afloader.c`.  Please check.  It doesn't make any sense for SVG
glyphs to run the auto-hinter.


    Werner


[*] I did `git rebase -i HEAD^^^^^`, then walking over the code commit
    by commit, adding my changes with `git commit --amend`.  If I
    found new things I did rebasing again so that the changes get
    added to the right commit.