Apply corrections from the "include what you use" tool

Generally cleanups of the includes. Making sure each file
can properly stand on its own and forward declares when possible.

include/chaiscript/language/chaiscript_algebraic.hpp

@@ -7,6 +7,8 @@
 #ifndef CHAISCRIPT_ALGEBRAIC_HPP_
 #define	CHAISCRIPT_ALGEBRAIC_HPP_
 
+#include <string>
+
 #include "../dispatchkit/dispatchkit.hpp"
 
 namespace chaiscript

include/chaiscript/language/chaiscript_common.hpp

@@ -5,10 +5,24 @@
 // http://www.chaiscript.com
 
 #ifndef CHAISCRIPT_COMMON_HPP_
-#define	CHAISCRIPT_COMMON_HPP_
+#define CHAISCRIPT_COMMON_HPP_
 
+#include <algorithm>
+#include <memory>
 #include <sstream>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+#include "../chaiscript_defines.hpp"
+#include "../dispatchkit/boxed_value.hpp"
 #include "../dispatchkit/dispatchkit.hpp"
+#include "../dispatchkit/proxy_functions.hpp"
+#include "../dispatchkit/type_info.hpp"
+
+namespace chaiscript {
+struct AST_Node;
+}  // namespace chaiscript
 
 namespace chaiscript
 {

include/chaiscript/language/chaiscript_engine.hpp

@@ -7,10 +7,27 @@
 #ifndef CHAISCRIPT_ENGINE_HPP_
 #define CHAISCRIPT_ENGINE_HPP_
 
+#include <cassert>
+#include <cstring>
+#include <algorithm>
 #include <exception>
 #include <fstream>
+#include <functional>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <vector>
 
 #include "../chaiscript_defines.hpp"
+#include "../chaiscript_threading.hpp"
+#include "../dispatchkit/boxed_cast_helper.hpp"
+#include "../dispatchkit/boxed_value.hpp"
+#include "../dispatchkit/dispatchkit.hpp"
+#include "../dispatchkit/dynamic_cast_conversion.hpp"
+#include "../dispatchkit/proxy_functions.hpp"
 #include "chaiscript_common.hpp"
 
 #if defined(__linux__) || defined(__unix__) || defined(__APPLE__)
@@ -28,9 +45,9 @@
 #endif
 
 
-#include "chaiscript_prelude.chai"
-#include "chaiscript_parser.hpp"
 #include "../dispatchkit/exception_specification.hpp"
+#include "chaiscript_parser.hpp"
+#include "chaiscript_prelude.chai"
 
 namespace chaiscript
 {

include/chaiscript/language/chaiscript_eval.hpp

@@ -7,10 +7,36 @@
 #ifndef CHAISCRIPT_EVAL_HPP_
 #define CHAISCRIPT_EVAL_HPP_
 
+#include <assert.h>
+#include <cstdlib>
+#include <exception>
+#include <functional>
+#include <limits>
 #include <map>
+#include <memory>
+#include <ostream>
+#include <stdexcept>
+#include <string>
+#include <vector>
 
-#include "chaiscript_common.hpp"
+#include "../chaiscript_defines.hpp"
+#include "../dispatchkit/boxed_cast.hpp"
+#include "../dispatchkit/boxed_cast_helper.hpp"
+#include "../dispatchkit/boxed_number.hpp"
+#include "../dispatchkit/boxed_value.hpp"
+#include "../dispatchkit/dispatchkit.hpp"
+#include "../dispatchkit/proxy_functions.hpp"
+#include "../dispatchkit/proxy_functions_detail.hpp"
 #include "../dispatchkit/register_function.hpp"
+#include "../dispatchkit/type_info.hpp"
+#include "chaiscript_algebraic.hpp"
+#include "chaiscript_common.hpp"
+
+namespace chaiscript {
+namespace exception {
+class bad_boxed_cast;
+}  // namespace exception
+}  // namespace chaiscript
 
 namespace chaiscript
 {

include/chaiscript/language/chaiscript_parser.hpp

@@ -7,11 +7,17 @@
 #ifndef CHAISCRIPT_PARSER_HPP_
 #define CHAISCRIPT_PARSER_HPP_
 
+#include <cstdint>
+#include <cstring>
 #include <exception>
 #include <fstream>
+#include <iostream>
+#include <memory>
 #include <sstream>
-#include <cstring>
+#include <string>
+#include <vector>
 
+#include "../dispatchkit/boxed_value.hpp"
 #include "chaiscript_common.hpp"
 
 namespace chaiscript