make RecursiveExtractor faster

[zangetsudo]

1. i have went though the souce code, and found that the 'AreIdentical' function which will do a full compare with the existed files which in the parent list, i dont know how it's necessary to compare all the file content, rather then the file names
2. it's possable to do Recursive Extract in real-parallel with https://www.isolineltd.com/blog/how-to-extract-a-zip-archive-in-parallel.html ?? becuse current version is very-very slow under my test.

regards, mike