as complained in issue #46, this PR proposes change to make bats less anoying and more logical. This PR tries to make:
Bat available above see level if there is dark stony caverns (extends spawn range from 0 to +128).
Bat should not spawn in well lit (even stony) caverns - it needs light < 7 (from 0-15 scale) to spawn. Cant spawn in daylight.
Bat should set its home in poorly lighten places (light <6)
Bat guanno production should not depend from protection, but from light (again <6 is required) which allows:
a. in multiplayer mode allows to make protected from griefing "guano farms".
b. in singleplayer mode does not require protection blocks to defend against bats.
c. logically (as in Real life) the best protection against bats is lighting underground (and now stony environment above sea level). Dark stony places will contain guano and bats as would be expected.
as complained in issue #46, this PR proposes change to make bats less anoying and more logical. This PR tries to make: