[HB] Further modularize Context matching
[HB] Further modularize Context matching

Distrotech/pango,Distrotech/pango,OpenInkpot-archive/iplinux-pango1.0,zsx/pango,OpenInkpot-archive/iplinux-pango1.0,kari-lentz/alpha-pango,danny-ku/pango,danny-ku/pango,kari-lentz/alpha-pango,kari-lentz/alpha-pango,Distrotech/pango,zsx/pango,zsx/pango,OpenInkpot-archive/iplinux-pango1.0,danny-ku/pango,kari-lentz/alpha-pango,zsx/pango