Fixed a few clang warnings.

src/Blocks/BlockPluginInterface.h

@@ -1,8 +1,14 @@
 
 #pragma once
 
+/** This interface is used to decouple block handlers from the cPluginManager dependancy through cWorld.
+The block handlers call this interface, which is then implemented by the specific classes that
+the caller provides.
+*/
 class cBlockPluginInterface
 {
 public:
+	virtual ~cBlockPluginInterface() {}
+	
 	virtual bool CallHookBlockToPickups(cEntity * a_Digger, int a_BlockX, int a_BlockY, int a_BlockZ, BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, cItems & a_Pickups) = 0;
 };