Initial commit of C QFS API bindings

This changeset includes the C-compatible wrappers for C++ QFS API. Calls wrap
C++ functions and methods with idiomatic C types and function calls. Every
effort was made to expose full functionality, but small omissions were made
where calls seemed inconsitent or where the API was incomplete on the C++ size.

Documentation is fairly complete in the header, but may need some adjustments
for clarity or grammar.