* Few code updates
* Do not show average RTT before timing out
* Fix unwanted integer division in RTTStatistics
* Fix float format, prettier jitter calculation
* Use +=, 0.1f -> 100.0f for stronger average updates
* Add session_t typedef + remove unused functions
u16 peer_id is used everywhere, to be more consistent and permit some evolutions on this type in the future (i'm working on a PoC), uniformize u16 peer_id to SessionId peer_id
* Move Connection threads to dedicated files + various cleanups
* ConnectionReceiveThread::processPacket now uses function pointer table to route MT packet types
* Various code style fixes
* Code style with clang-format
* Various SharedBuffer copy removal
* SharedBuffer cannot be copied anymore using Buffer
* Fix many SharedBuffer copy (thanks to delete operator)
