1) Giving "-g" or "--gdb" as the first argument to the dfhack script
will launch DF under gdb.
2) "reset -I" is called after DF finishes, to return the terminal to a
sane state in case DF crashed or was killed.
Copy package/linux/dfhack to the games directory; it's the same as the
normal df script, but sets LD_PRELOAD properly.
Also, CMAkeLists.txt now checks to see that the output directory is set
to the game directory, and fatally fails if it isn't.
Petr Mrázek
Matthew Cline