Make include-what-you-use happy with files in source/network and
fix what needs to be fixed.
Ref: #8086
Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
This fixes packet loss issues on some VPN solutions.
Patch By: sera
Differential Revision: https://code.wildfiregames.com/D4967
This was SVN commit r27599.