Add support for font weight and stretch selection when using system fonts.
Add function to get system fallback font from a font name, style, text, and language code.
Implement system font support for Android.
Use system fonts as a last resort fallback.
They haven't been updated for years and still use the old MainLoop
basic framework instead of the new doctest one.
They're of dubious quality and best redone from scratch using the
new framework.
Fix "Fill" alignment processing wrong side of the text if overrun trim was applied.
Improve "Fill" alignment to avoid adding excessive subsequent spaces or elongations.
Add font detection to the overrun, to correctly add ellipsis (was using last glyph font, which doesn't necessary have dot character).
Improve line breaking to avoid adding excessive subsequent soft break points for languages without word separator.
Port missing overrun/justification code to the Fallback text server.
Fix inferred text direction detection by controls.
Add tests for "Fill" alignment and line breaking glyph flags.
