- move pointer left padding macro into single header file.
- move utf8 fopen into single header but not finished.
- add testbench for pointer left padding macro.
- add system pointer size detector according to new migrated features requested.
- add endian and compiler detector, and modify os detector.
- now we use CMake to add detector-used macro, instead of using some C++ features to detect them.
- change Windows environment detection according to the change of os detector.
