Update Russian translation
Update po files
Display serverlist flags as icons
Remove vertlabels from main menu and relayout a bit
Fix segfault when dragging mouse out of mainmenu window (#1910)
Merge remote-tracking branch 'minetest/master' into stable

Conflicts:
	po/it/minetest.po
	textures/base/pack/blank.png
	textures/base/pack/server_flags_creative.png
	textures/base/pack/server_flags_pvp.png
merge fix