Block populators extend beyond their chunk

[ferrybig]

Because Block populators extend beyond their chunk, stack overflow exceptions may happen during the creation of worlds

[ferrybig]

There are 3 main types of world populations that need changing (they could all use a differend strategies for this bug)

• No outside chunk access (those shouldn't give any problems (think of the snow populator))
• Check outside chunk (Think of the water populator, that needs to check surrounding tiles)
• Place outside chunk (think of a dungeon populator)
• Check & get outside of the chunk (Think of the ore generator not wanting to overwrite blocks)