Better Launchers (0.21.8 Alpha)

This update brings changes to the launcher shell script and the windows EXEs that start the game.

Each of these now searches for a directory named 'jvm' in the game's directory for a Java Virtual Machine (JVM) to use to run the game.  Failing that, it launches the game using the older method from previous versions.

However I also made some tweaks to the shell script launcher, so it now looks for a bundled JVM, then looks for one via the 'JAVA_HOME' environment variable and finally searches for it on the 'PATH' environment variable.  This is a slight change-up in order, as it used to search the path before 'JAVA_HOME'.  I also modified the shell script to include some newer places to search for a JVM (if it doesn't find one) and generally made the error dialog box and messages easier to read.