[Client] Removed the use of a package that doesn't work on mac.
[Client] Added a button for the help window.
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.
[Download] Renaming output file of download/launch application

The download and launch application will now be named illarion.jar
instead of downloader.jar