All 1-character strings converted to primitives

"b" + "r" now changed to 'b' + 'w'.  It's more straight-forward, and may cause perfomance improvements - character primitives allocation is faster and less expensive than string creation.

Mage/src/main/java/mage/abilities/common/PutCardIntoGraveFromAnywhereAllTriggeredAbility.java

@@ -78,7 +78,7 @@ public class PutCardIntoGraveFromAnywhereAllTriggeredAbility extends TriggeredAb
                 sb.append("your");
                 break;
             default:
-                sb.append("a");
+                sb.append('a');
         }
         sb.append(" graveyard, ");
         ruleText = sb.toString();