NBT release 1.5.1

Support for Python 3.10; Update chunk.py; other minor bug fixes

Improve version to 1.5.0.

Change indentation tabs to spaces.

Bump version number to 1.4.0.

Note that VERSION now contains a patch revision ("1.4.0" instead of "1.4").
This is the last version that contains tabs for indentation.

Merge remote-tracking branch 'github/macfreek/world-examples'

Merge pull request #25 from Fenixin/small-fix

Fix missing asterisk.

Merge remote branch 'MidnightLightning/master'

* Lots of cleanup. 
* Regionfiles now work correctly.
* Chunk convenience class added.
* Started work on Docs. 
* Filename handling in write_file better.
* All tests now pass.

updated package