COMMON: The common library can now be used independently by any number of features.
COMMON: The common library no longer restricts HAVE_SOCKET_LEGACY.
Netplay Task: Network interface scoring changed from byte-level to bit-level.
Reordered netplay and NAT structs to follow the coding guidelines more closely.
Moved part of the chat struct out of the program's image and into the heap.
For the time being, if NAT traversal is successful it simply announces
it as an OSD message. In the future it will be used to inform a
matchmaking server of the public port.
This patch also included minor fixes to the NAT traversal implementation
to make the select it demands actually doable.
Adding NAT traveral interface to libretro-common, with (currently) a
backend support MiniUPNPC. Sensible future backends would be libupnp and
a direct implementation of PCP/NAT-PMP.
Cthulhu-throwaway