Add HistoryManager
Update .gitignore
Revert "Update .gitignore"

This reverts commit 00bd49f6248b501256be4221a84956d786b66d4d.
Revert "Add HistoryManager"

This reverts commit f41552c0bd2b10eaaa9fad7e7d5634238e9db6fe.
Merge pull request #18 from Wohlstand/master

Merge to Update 18
Add/Improve the first (nearly) complete historyoperation.
Merge pull request #19 from Wohlstand/master

Merge to Update 19
Merge branch 'master' of https://github.com/KevinW1998/PlatGEnWohl.git
Merge pull request #14 from KevinW1998/master

Improval towards HistoryManager