Create minetest.xml

Tested on Chakra 2014.02 "Curie", Minetest 0.4.9
After a few weeks of using minetest, this cleaner erased:
  Cache: 39.0 MiB
  Debug logs: 595.4 MiB
  Favorite server list: 828 B
  Total: 634.4 MiB
(Mod settings & Mods will vary greatly depending on the user, so they aren't included in above stats)
home page: http://www.minetest.net/
Popularity stats: Currently has roughly 30 public servers: http://servers.minetest.net/