This adds a new structure 'Typeface' to the FontDatabase that
represents all fonts of the same family and variant.
It can contain a list of BitmapFonts with varying size but of
the same family and weight or a pointer to a single TTF font
for all sizes of this Typeface.
We have both the normal menu items and keyboard shortcuts for these by
now. No need to have always-visible buttons -- makes the app more
consistent with the other apps, and makes it use up less vertical space.
Now that WindowServer broadcasts the system theme using an anonymous
file, we need clients to pledge "recvfd" so they can receive it.
Some programs keep the "shared_buffer" pledge since it's still used for
a handful of things.
