core: Move send ping packets functions to ping.c
core: Move send ping packets functions to ping.c
Merge branch 'dev'

Conflicts:
	core/packets.h
	core/ping.c
core: Move ping request/response into ping.c
Merge branch 'master' of https://github.com/plutooo/ProjectTox-Core into plutooo-master

Conflicts:
	core/ping.c
	core/util.c