Some performance or memory optimizations

Replaced String concat in loops with StringBuilder (performance)
Replaced for with keySet + Map.get() through for with entrySet (perf)
Changed inner classes to static classes, mostly struct like (memory)

src/main/java/appeng/me/Grid.java

@@ -3,6 +3,7 @@ package appeng.me;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import appeng.api.AEApi;
@@ -34,10 +35,10 @@ public class Grid implements IGrid
 		this.pivot = center;
 
 		HashMap<Class<? extends IGridCache>, IGridCache> myCaches = AEApi.instance().registries().gridCache().createCacheInstance( this );
-		for (Class<? extends IGridCache> c : myCaches.keySet())
+		for (Entry<Class<? extends IGridCache>, IGridCache> c : myCaches.entrySet())
 		{
-			bus.readClass( c, myCaches.get( c ).getClass() );
-			caches.put( c, new GridCacheWrapper( myCaches.get( c ) ) );
+			bus.readClass( c.getKey(), c.getValue().getClass() );
+			caches.put( c.getKey(), new GridCacheWrapper( c.getValue() ) );
 		}
 
 		postEvent( new MENetworkPostCacheConstruction() );

src/main/java/appeng/me/NetworkEventBus.java

@@ -4,6 +4,7 @@ import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Hashtable;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import appeng.api.networking.IGridNode;
@@ -14,7 +15,7 @@ import appeng.core.AELog;
 public class NetworkEventBus
 {
 
-	class NetworkEventDone extends Throwable
+	static class NetworkEventDone extends Throwable
 	{
 
 		private static final long serialVersionUID = -3079021487019171205L;
@@ -129,17 +130,17 @@ public class NetworkEventBus
 		{
 			if ( subscribers != null )
 			{
-				for (Class o : subscribers.keySet())
+				for (Entry<Class, MENetworkEventInfo> subscriber : subscribers.entrySet())
 				{
-					MENetworkEventInfo target = subscribers.get( o );
-					GridCacheWrapper cache = g.caches.get( o );
+					MENetworkEventInfo target = subscriber.getValue();
+					GridCacheWrapper cache = g.caches.get( subscriber.getKey() );
 					if ( cache != null )
 					{
 						x++;
 						target.invoke( cache.myCache, e );
 					}
 
-					for (IGridNode obj : g.getMachines( o ))
+					for (IGridNode obj : g.getMachines( subscriber.getKey() ))
 					{
 						x++;
 						target.invoke( obj.getMachine(), e );

src/main/java/appeng/me/cache/CraftingGridCache.java

@@ -86,7 +86,7 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 	final private SetMultimap<IAEStack, CraftingWatcher> interests = HashMultimap.create();
 	final public GenericInterestManager<CraftingWatcher> interestManager = new GenericInterestManager<CraftingWatcher>( interests );
 
-	class ActiveCpuIterator implements Iterator<ICraftingCPU>
+	static class ActiveCpuIterator implements Iterator<ICraftingCPU>
 	{
 
 		final Iterator<CraftingCPUCluster> i;

src/main/java/appeng/me/cluster/implementations/CraftingCPUCluster.java

@@ -58,7 +58,7 @@ import cpw.mods.fml.common.FMLCommonHandler;
 public class CraftingCPUCluster implements IAECluster, ICraftingCPU
 {
 
-	class TaskProgress
+	static class TaskProgress
 	{
 
 		long value;

src/main/java/appeng/me/storage/MEMonitorIInventory.java

@@ -27,7 +27,7 @@ import appeng.util.inv.ItemSlot;
 public class MEMonitorIInventory implements IMEInventory<IAEItemStack>, IMEMonitor<IAEItemStack>
 {
 
-	class CachedItemStack
+	static class CachedItemStack
 	{
 
 		public CachedItemStack(ItemStack is)