Added systemsShutdown() to main for testing

Just included it because it's a thing in World now.
Added extra flag for debugging

The -g flag allows for exact line numbers to show during debug/Valgrind testing
Fixed linkLibrary() argument passing

The stupid referencing/dereferencing shenanigans were still acting up,
so I think I finally fixed how it's handled.

There's also a small change to a cerr statement, namely for a system
shutdown thing.