Source folder fix, JSONUtils.java, last modified time

Also, I put in a last selected directory feature (It's commented ("//") for your test folder) for each session

+ Could you autoformat all the code (Right click project -> Source -> Format)
+ ... -> Source -> Organise

* You can probably close my old pull request (https://github.com/Watchful1/PermissionsChecker/pull/4), this one is better!