Release v0.17.0

Merge pull request overviewer#1791 from overviewer/116-blocks

Release 0.15.0

tagging version 0.14.0

tagging version 0.13.0

This is the last commit that supports Minecraft <1.13, before the blo…

…ck id

format was changed.

Bump versions and docs for 1.8 support!

Fix rendering of large portals

Fixes issue overviewer#1009

this is the last commit that supports the old texture format (using

terrain.png) before Minecraft switched to Resource Packs.

this is the last commit that supports old region formats (.mcr),

before Minecraft switched to the Anvil format (.mca)