Release 0.30 (ungarj#223)

* updated changelog

* updated docs

* updated changelog

increased version to 0.29; updated changelog

WIP Update doc (ungarj#196)

updated readme & docs

updating changelog, tagging 0.27

extended magic methods to handle BufferedTiles

make execute() not require explicit '**kwargs'

updated README & CHANGELOG

updated Readme, tagged 0.23 release

update changelog & version number

default max_chunksize to 1 (ungarj#113)