Mob bugfixes

* Mobs no longer require constant line-of-sight to a player to remain
aggravated
* Fixed an ASSERT
* Fixed mobs jumping
* Fixed Idle state not properly using AI
+ Added FILE_IO_PREFIX to favicon loading
+ Implemented #563

src/Generating/ChunkGenerator.cpp

@@ -223,6 +223,8 @@ void cChunkGenerator::Execute(void)
 
 		if (m_Queue.empty())
 		{
+			// Sometimes the queue remains empty
+			// If so, we can't do any front() operations on it!
 			continue;
 		}