Finishes work started in f3aedf88a6.
This removes the boost-CPP function wrappers entirely, in favour of pure
templated code in FunctionWrapper.h
The Call* functions were already heavily templated, so there is nothing
really new here. I just use tag dispatch to reduce the number of
overloads slightly.
The new functions do not need the script interface, only the script
request.
Differential Revision: https://code.wildfiregames.com/D3912
This was SVN commit r25354.