Revert "Revert "Altered most IO Operations to use NIO.2 and AutoCloseable try statements""

This reverts commit 2dbfa7be70e47c91f10416f2e99087d208a528ae.
Automatic cleanup of the import statements
[Common] Fixed unknown loading error in directory manager
[Client] Removed the use of a package that doesn't work on mac.
[Client] Added a button for the help window.
[Common] Fixed resolving absolute directories in the directory manager
[Common] Fixed usage of wrong exception
Revert "[Client] Removed the use of a package that doesn't work on mac."

This reverts commit 0ebe1092a45d788d1a3aa0129377853f344204b5.
Merge commit '4d80d8bd7c592ba531b14ae20066a9f14765cd02' into develop
[Client] Showing a dialog if connection is lost.