header files include mess about dtkcore

[Decodetalkers]

I must say, you need to read more cpp repo learn more about this language..

If you have not write cpp before, and before you contribute to our repo, you need some training.. I am glad that you want to make contribution.. And there is may code need to update, like the suggestion by compiler, the code needs clippy check, to remove so many warning.. but you need to learn cpp first

[ccmywish]

@Decodetalkers Thanks for your advice and patience. I'll learn more before working on it and contributing to this.