Xie Gengxin

Results 4 issues of Xie Gengxin

# Bugs ConcurrentHashMap allocates memory by std::allocator, which won't generate memory aligned at 64B. This has caused coredump when I compiled with `clang14` and `-mavx2`: **Clang14** ![image](https://user-images.githubusercontent.com/57653828/186337551-4632c836-ca55-435d-ad85-027b35d255da.png) **Clang14 IR** ![image](https://user-images.githubusercontent.com/57653828/186337688-91a2a724-b964-4465-beb9-172061bd8685.png)...

ClearStack() function in document.h misses check allocator type. This would cause memory leak if parse failed. Such as following code: ```c++ int main() { if (1) { rapidjson::Document doc; auto&...

This PR provides a new handler that can parse json for a given schema.

# Main Changes - Implement MergePatch and Merge API following [RFC 7386](https://www.rfc-editor.org/rfc/rfc7386) API. - Provide UpdateFrom and Update API - Remove GenericNode template parameter **Allocator**.