Bug fixes with structure generation and Debug System.

I fixed many bugs with the structure generation and I made a new debugging system.

Bug fixes:
   -Fixed items generating with stack size of 0;
   -Fixed the structure generating on trees or on the water
Debug system:
   -Now if you need a debug message for something, you can just use a method called sendDebugMessage inside the Debugger class. You would need to set your configuration value of debug messages to true to see them.