Linux/OSX runtime image support

[lord-brimstone]

The runtime images for Linux and OSX were never tested because we didn't have access to those platforms. This issue will cover known problems in the images. (Error text taken from Mandarbmax on the Dominions discord server)

• Launcher shell script needs to be marked as executable

• java needs to be marked as executable

• fix trailing spaces on lines in launcher shell scripts

• fix windows-style line-endings in launcher shell scripts
  /home/maxwell/Downloads/NationGen-0.7.0-RC10/NationGen: line 2: $'\r': command not found

• Path to included java executable invalid
  /home/maxwell/Downloads/NationGen-0.7.0-RC10/NationGen: line 3: /bin/java: No such file or directory This is a result of the bad line endings

The nationgen jar can still be accessed normally using an appropriate version of java that is already installed:
java -jar '/home/maxwell/Downloads/NationGen-0.7.0-RC10/lib/NationGen-0.7.0-RC10.jar'

[lord-brimstone]

So, I think we can't fix the first two items on Windows, because files being marked as executable is a linux/osx thing. To confirm, I tried giving Mandarbmax the script, he marked it executable and gave it back, I downloaded and gave it right back to him, and it was no longer flagged for execution.

I think we'd need to actually be on linux or osx and then tar and gzip the files? Then maybe the flags stay? So until that's accessible or we feel comfortable with having someone else do it, I think we have to live with the end user having to manually mark the launchers and java as executable themselves. Probably should make a note about it on the release page.