Unification of Text Layout Week 1

[Akash Jain]

During the first week, I have added platform independent experimental
support for building HarfBuzz using the --with-harfbuzz flag.
I am also working on the new layout class. Most of the work has been
in extending the platform specific faces to supply the new layout
class with the required data.
This is finished. I will continue working on the new class in the current week.

Regards,
Akash