Add Trapdoor Functions to cWorld and fix Trapdoor Redstone Bugs
More documentation (thanks to madmaxoft) and use GetBlockTypeMeta
Add cancelling to WeatherChanging event.
Merge pull request #746 from Howaner/Slabs

Add Trapdoor Functions to cWorld and fix Trapdoor Redstone Bugs
Fixed previous weather changes.

cWorld::GetDefaultWeatherInterval() returns -1 for unknown weather.
Attempted Changes to Pistons