Fix segfaults & include test assets (major refactor).

Fix reentrancy complaints from GHC, attempt to fix segfault.

Add documentation & corrected type signatures.

Add, test, & fix shaping function.

Draft language bindings to font/face APIs.

FreeType integration is not threadsafe, not that in API design.

Design FreeType2 integration.

Draft pure-functional Harfbuzz API.