Added resolvers.levelup() (check how it works on ToME's dragons)

resolvers.talents{} can now take a table for each talent value which specifies how and when the talent is level'ed up
Dragons have lost summoning; but they are now more formidable foes


git-svn-id: http://svn.net-core.org/repos/t-engine4@2910 51575b47-30f0-44d4-a5cc-537603b46e54