All packet creating methods now create Packet instead of byte[]

This commit got way too big...
- Remove deprecated methods for sending packets
- Favor OutPacket & Packet over MaplePacketLittleEndianWriter, LittleEndianWriter, and byte array
- Split up some packet creating methods into separate classes

src/main/java/net/server/channel/handlers/UseOwlOfMinervaHandler.java

@@ -59,6 +59,6 @@ public final class UseOwlOfMinervaHandler extends AbstractMaplePacketHandler {
             }
         }
         
-        c.announce(PacketCreator.getOwlOpen(owlLeaderboards));
+        c.sendPacket(PacketCreator.getOwlOpen(owlLeaderboards));
     }
 }