Add Save and Load Actions to Editor and fix Windows Build
-> use FileHandler
-> flush buffer before closing streams
-> move FileHandling in ClEditor
-> replace useless Macor GDK_WINDOW_HANDLE
Merge branch 'master' of https://github.com/Streamstormer/PanicSim
Revert "Add Save and Load Actions to Editor"

This reverts commit 9ec45e14cbcd305f693d2224f4bebabbf9a12124.