Port lasem to harfbuzz

[EmmanuelP]

It looks like that is the current way we should implement text rendering.

[EmmanuelP]

Hopefully it would fix the dotted circle issue. This is what lasem does:

While it should be rendered like this:

If someone know how to fix this issue using pango, please let us know.

[khaledhosny]

You can try adding a space or ZWSP before the combining mark.