Apply changes applied from clang-modernize

Needed 1-2 cleanups by hand. 99% was automatic.

* The version that ships with ubuntu 14.04 seems to not work.
  I had to build from scratch

* Use cmake to generate the build commands that clang-modernize wants

```sh
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS:bool=true ../ChaiScript/
```

* Use the clang-modernize tool. Note that you have to be pretty explicit
  about the include paths if you want it to also update your include
  files

```sh
../llvm-build/bin/clang-modernize ../ChaiScript/src/*.cpp -for-compilers=gcc-4.8 -include /home/jason/ChaiScript/include,/hjason/ChaiScript/include/chaiscript,/home/jason/ChaiScript/include/chaiscript/dispatchkit,/home/jason/ChaiScript/include/chaiscript/language -p compile_commands.json
```

* In my case, it left some unused `typedef`s behind, which I cleaned up.

include/chaiscript/dispatchkit/function_call.hpp

@@ -31,7 +31,7 @@ namespace chaiscript
       std::function<FunctionType>
       functor(const std::vector<Const_Proxy_Function> &funcs, const Dynamic_Cast_Conversions *t_conversions)
       {
-        FunctionType *p=0;
+        FunctionType *p=nullptr;
         return detail::build_function_caller_helper(p, funcs, t_conversions);
       }