chunk paths are now preloaded lazily
chunk paths are now preloaded lazily

this odd double indirection is because level.presentChunks is presented as a list of tuples, while level._presentChunks is used internally to map the tuples to InfdevChunks

mcedit/pymclevel,codewarrior0/pymclevel,mcedit/pymclevel,arruda/pymclevel,codewarrior0/pymclevel,arruda/pymclevel,ahh2131/mchisel,ahh2131/mchisel