Merge pull request #360 from mc-server/redstonefixes

Fixed piston sound effect (when unable to extend)
Removed the bloody sdf file.
Ignoring SDF files.
Added cWorld:ForEachBlockEntityInChunk() and cWorld:DoWithBlockEntityAt() functions.

Also exported them to the Lua API.
Debuggers: Test harness for cWorld:ForEachBlockEntityInChunk().

The fill command will fill all empty slots in block entities with containment with gold nuggets, one per slot.
APIDump: Documented cWorld:ForEachBlockEntityInChunk() and cWorld:DoWithBlockEntityAt().
Exported static XP calculation to Lua API.
APIDump: Documented cPlayer XP-related functions.
Changed cRoot:GetFurnaceRecipe() Lua binding signature.

Fix #364.
Debuggers: Added a test harness for cRoot:GetFurnaceRecipe().

The "/fr" command lists the furnace recipe for the currently held item.
APIDump: Documented new cRoot:GetFurnaceRecipe().
Fixed cRoot:GetFurnaceRecipe() Lua binding.
Added cRoot:GetFurnaceFuelBurnTime() to Lua API.
APIDump: Fixed cRoot's furnace query API.
Added cFile:GetFolderContents().

Fix 162.
APIDump: Implemented constant groups.

Fix #289.
APIDump: Added a few constant groups to the descriptions.
APIDump: Added more constant groups.

Also fixed the parsing of the Include data in the constant groups, and added linkification to group texts.
Added cFile:ReadWholeFile() to Lua API.
Fixed Lua bindings for cFile:GetFolderContents().