Move userData on Mac to `~/Library/Application Support/Koala/UserData`
* Change `FileManager.userDataDir` to `~/Library/Application Support/Koala/UserData` on Mac
* Add a migration system to `main.js` to move files from `~/.koala` to the new dir
Merge branch 'feature/better-mac-support' into concept
* new option type `description`

* visible properties localization
Add Compile Class