Network packets have network byte order

[AJenbo]

[Eider-McDuck]

Now with endian_cast.

[glebm]

Error:

Source/multi.cpp:647:57: error: cannot pass non-trivial object of type 'devilution::int32_net_t' (aka 'endian_int<int, SwapBE>') to variadic function; expected type from format string was 'int' [-Wnon-pod-varargs] app_fatal("Invalid size of game data: %d", gameData->size);

This needs an explicit cast, implicit one doesn't work here.

This is part of the reason I don't like implicit casts :)

[glebm]

Looks like if constexpr is not supported on GCC 6 at all