- Remove redundant function configurations for the same function since
it is not (yet) possible to configure overloaded functions. Instead mark
the optional arguments with `default="0"` so the configuration works
with a different number of arguments.
- Add documentation to boost.cfg (links and function declarations).
- Rearranged configurations so functions, defines, ... are together now.
- Add `direction` for function arguments where applicable.
- Add some tests to boost.cpp.
Sebastian