Add support for CGContextSetFontSmoothingStyle
Add support for CGContextSetFontSmoothingStyle

This enables narrower rendering of glyphs and it tends to look a bit
better. iTerm2 and Terminal both do this.

dannydulai/alacritty,dannydulai/alacritty,jwilm/alacritty,alacritty/alacritty,jwilm/alacritty,alacritty/alacritty,jwilm/alacritty,jwilm/alacritty