Add new IsWeatherWet hook for cauldrons.

@madmaxoft can you comment?
Add DoxyComments to he weather things. 

Also changed the function names.
Updated unnecessary function :/
SMICOLOSL

Meant to be semicolons up there.
Update APIDesc.lua
Update APIDesc.lua
IsWeatherSunnyAt does something useful :D
Reduced code duplication

call @maxmaxoft!
calling...
call connected (0:20)
call ended
Compile fix
Fixed constness
Merge pull request #1082 from mc-server/cauldronfixes

Add biome-aware downfall functions.