qtscript: Add new cheat 'jsload' which allows you to load any AI script you
want from the 'scripts' directory in your write directory to run on the current
player. New script global 'scriptPath' holds the path to whereever you loaded
the script from, and is used automatically for include files. There is no longer
any need to specify any paths for include files if they are located in the same
directory as your main script.