Implements basic Thrift architecture

I set up the Thrift build system, and it compiles without any errors,
but doesn't do anything yet; all I have are some skeleton files for make
to see. I renamed the bots directory; the client/server division in the
bots code is becoming clearer, and once I figure out exactly which code
is needed from the libs for either client or server code, I'll probably
move some of the files from client/ to server/

Note: I'm not including any of the Thrift-generated files; if you don't
have the Thrift compiler/C++ hooks installed and can't generate them,
they're useless, since they need to be linked against thrift anyways