Fix labels and vertlabels on some systems.
Don't handle lack of IPv6 as fatal in unit tests
Fix server assert in case of invalid message from client, just kick that client.
Fix uncought deserialization error on receiving data
Support for scalable font and gui elements
Fix positioning of tabheader in order to be usable for scaling GUIs
WARNING: this changes position of current tabheaders, mods have to adjust!
Merge commit 'd4245e6' into merge3

Conflicts:
	builtin/mainmenu/init.lua
	src/constants.h
	src/server.cpp