Move code generator to tools subdirectory for higher consistency with OSS standards

tools/xml2cpp-codegen/generator_utils.h

@@ -0,0 +1,22 @@
+/**
+ * Inspired by: http://dbus-cplusplus.sourceforge.net/
+ */
+
+#ifndef __SDBUSCPP_TOOLS_GENERATOR_UTILS_H
+#define __SDBUSCPP_TOOLS_GENERATOR_UTILS_H
+
+#include <string>
+#include <sstream>
+#include <iomanip>
+
+const char *atomic_type_to_string(char t);
+
+std::string stub_name(const std::string& name);
+
+std::string signature_to_type(const std::string& signature);
+
+std::string underscorize(const std::string& str);
+
+constexpr const char* getHeaderComment() noexcept { return "\n/*\n * This file was automatically generated by sdbus-c++-xml2cpp; DO NOT EDIT!\n */\n\n"; }
+
+#endif  //__SDBUSCPP_TOOLS_GENERATOR_UTILS_H