[Fontconfig] Changing to hintslight globally by default + hintfull for otfs

[Piotr Jurkiewicz]

I would like to express my support for setting hintslight by default. I
also find font rendering on Ubuntu superior in comparison to the present
defaults. After switching to Arch, I was dissatisfied with the font
rendering here. I found out that copying Ubuntu's 10-hinting-slight.conf
file fixes the problem. As you may know, Arch package maintainers are
reluctant to include custom patches in their packages. So upstreaming
these changes is the only way to make it default in Arch and other
distributions which do not patch fontconfig with their custom settings.

Ubuntu also includes 10-antialias.conf and 10-hinting.conf settings by
default. However, I didn't notice any difference with and without these
files (at least in Qt4 apps). Therefore, I think that before including
these config files, first it should be checked if these settings
aren't already default.