Update nbt library.
Changes everywhere, a commit in the middle of a big changes.
First version with too small region files detection and replacement.
When double clicked in windows it now prints a helpful msg.
Halfway of big changes.
Print which region file caused the ChildProcessException.
Properly handle the new ChildProcessException stuff.
Update nbt library fixing some nasty bugs.

Checking for chunks sharing offsets now works as expected.

Moved some functions to util.py.
Big restructuring of region-fixer.py.

Fixed a few bugs with the new sharing offset problem.
Simplified a few things in region-fixer.py.
Removing too-small-regions now works.
Replace region files works now. Fixed some todos in the summary option.
Fixed a few todos in world.py.
Fixed TODOs in scan.py.
Solve todos in util.py.
Updated interactive mode to get all the new options. Improved the handling of new problems and how to interate them.
Update interactive.py help.
Add donors.txt and move sponsor info there.
Bump version number.
Some text changes.

Fix trying to get a chunk from non-existant key throwing KeyError.

Fixed some changes in variable.
Fix mixing up the regionsets.