This is what old HB does. Morever, fixes rendering with Win8 malgun
font. The Win7 version doesn't compose with either Uniscribe nor HB,
but Win8 version works as expected, like Uniscribe, with this change.
Lets call Hangul done for now.
Previously, we were NOT actually recomposing Hangul Jamo. We do now.
The two lines in:
test/shaping/texts/in-tree/shaper-default/script-hangul/misc/misc.txt
Now render the same with the UnDotum.ttf font. Previously the second
linle was rendering boxes.
We can also start applying OpenType Jamo features later. At this time,
I have no idea how the 'ljmo', 'vjmo', 'tjmo' features are supposed to
work. Maybe someone can explain them to me?