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/handlers/login/SetGenderHandler.java

@@ -40,7 +40,7 @@ public class SetGenderHandler extends AbstractMaplePacketHandler {
             byte confirmed = slea.readByte();
             if (confirmed == 0x01) {
                 c.setGender(slea.readByte());
-                c.announce(PacketCreator.getAuthSuccess(c));
+                c.sendPacket(PacketCreator.getAuthSuccess(c));
 
                 Server.getInstance().registerLoginState(c);
             } else {