Fix + minor cleanup.
Avoids useless random.choices.
Introduces decent tree generation.
Merge branch 'master' of https://github.com/boskee/Minecraft
Typo.
Adjusts tree parameters.
Merge branch 'master' of git://github.com/avelanarius/Minecraft
Restored "hold to dig" functionality (like in MC)
Merge commit 'a552bce2c8549cd5dab18f9a9a5fe0849a450c80'
Fix default option of -terrain