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/DenyPartyRequestHandler.java

@@ -43,7 +43,7 @@ public final class DenyPartyRequestHandler extends AbstractMaplePacketHandler {
             
             if (MapleInviteCoordinator.answerInvite(InviteType.PARTY, chr.getId(), cfrom.getPartyId(), false).result == InviteResult.DENIED) {
                 chr.updatePartySearchAvailability(chr.getParty() == null);
-                cfrom.getClient().announce(PacketCreator.partyStatusMessage(23, chr.getName()));
+                cfrom.sendPacket(PacketCreator.partyStatusMessage(23, chr.getName()));
             }
         }
     }