Improve exceptions (#1256)

- Kick more exceptions further up the pipeline to be more likely to be shown to player
- Try to avoid lots of console spamming when it's the same error multiple times
- Allow parsing of FaweExceptions during commands to better give information to players

worldedit-core/src/main/java/com/sk89q/worldedit/extent/clipboard/Clipboard.java

@@ -273,10 +273,9 @@ public interface Clipboard extends Extent, Iterable<BlockVector3>, Closeable {
         }
         try {
             Operations.completeLegacy(copy);
-        } catch (MaxChangedBlocksException e) {
-            e.printStackTrace();
+        } finally {
+            editSession.close(); // Make sure editsession is always closed
         }
-        editSession.flushQueue();
         return editSession;
     }