Adding random_messages mod with simple messages
- Random messages mod by @arsdragonfly (http://github.com/arsdragonfly)
  has been added to the server mods.
Re-add texture for 3D-superapple
Right texture for unbreakable diamond block
Add kittens and improve the sounds code/name
Merge branch 'Ataron-diamond_textures'
Merge branch 'master' of http://github.com/Ombridride/minetest-minetestforfun-server
tweak mobs/kitten and random_messages

mobs/kitten :
- add the tamed funtionnality
(doesn’t work for the moment, the kittens don’t spawn)
- smalls other tweaks

Random_messages :
Try to send one message per half hour instead of one message per 2
minutes