Batch #3469 by eAthena: 0 byte-identical, 3 confirmed by peer review.
- fn_21572 DecodeSrcDst: logic confirmed by peer review
- fn_21589 SendPacketHeader: logic confirmed by peer review
- fn_21590 SendPacketHeader2: logic confirmed by peer review
Peer-reviewed-by: youko, superintelligence
Accepted without human review: peers confirmed the logic ("same" ahead by at least 3, with 70% of the votes).
Adds to the build: Source/Client/Mode/GameModeProtocol.cpp
