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/recipes/game/ShapedRecipe.java

@@ -31,10 +31,11 @@ public class ShapedRecipe implements IRecipe, IRecipeBakeable
 		return !disable;
 	}
 
-	public ShapedRecipe(ItemStack result, Object... recipe) {
+	public ShapedRecipe(ItemStack result, Object... recipe)
+	{
 		output = result.copy();
 
-		String shape = "";
+		StringBuilder shape = new StringBuilder();
 		int idx = 0;
 
 		if ( recipe[idx] instanceof Boolean )
@@ -57,7 +58,7 @@ public class ShapedRecipe implements IRecipe, IRecipeBakeable
 			for (String s : parts)
 			{
 				width = s.length();
-				shape += s;
+				shape.append( s );
 			}
 
 			height = parts.length;
@@ -67,7 +68,7 @@ public class ShapedRecipe implements IRecipe, IRecipeBakeable
 			while (recipe[idx] instanceof String)
 			{
 				String s = (String) recipe[idx++];
-				shape += s;
+				shape.append( s );
 				width = s.length();
 				height++;
 			}
@@ -75,13 +76,13 @@ public class ShapedRecipe implements IRecipe, IRecipeBakeable
 
 		if ( width * height != shape.length() )
 		{
-			String ret = "Invalid shaped ore recipe: ";
+			StringBuilder ret = new StringBuilder( "Invalid shaped ore recipe: " );
 			for (Object tmp : recipe)
 			{
-				ret += tmp + ", ";
+				ret.append( tmp + ", " );
 			}
-			ret += output;
-			throw new RuntimeException( ret );
+			ret.append( output );
+			throw new RuntimeException( ret.toString() );
 		}
 
 		HashMap<Character, Object> itemMap = new HashMap<Character, Object>();
@@ -97,19 +98,19 @@ public class ShapedRecipe implements IRecipe, IRecipeBakeable
 			}
 			else
 			{
-				String ret = "Invalid shaped ore recipe: ";
+				StringBuilder ret = new StringBuilder( "Invalid shaped ore recipe: " );
 				for (Object tmp : recipe)
 				{
-					ret += tmp + ", ";
+					ret.append( tmp + ", " );
 				}
-				ret += output;
-				throw new RuntimeException( ret );
+				ret.append( output );
+				throw new RuntimeException( ret.toString() );
 			}
 		}
 
 		input = new Object[width * height];
 		int x = 0;
-		for (char chr : shape.toCharArray())
+		for (char chr : shape.toString().toCharArray())
 		{
 			input[x++] = itemMap.get( chr );
 		}