Added SetTicksUntilWeatherChange/GetTicksUntilWeatherChange. to set/get the amount of ticks before the weather changes. Added SendBlockChange to Lua to create "fake" blocks

git-svn-id: http://mc-server.googlecode.com/svn/trunk@1572 0a769ca7-a7f5-676a-18bf-c427514a06d6