- resolver finalization: revert call sequence - from bottom to top
- add Lua type "resolver" for general resolvers without own identity
- make resolver argument check independent of resolver listing by adding
a mandatory entry "_resolver"=true to metatable of resolvers
- drawBorder, drawRectangle: allow arguments "key"+"resolver" instead of
"tile" for full usage of these methods in resolvers
- res.maze:
- avoid multiple initialization and finalization
- evaluate all keys by the complete subresolver chain by all renderers
