introduce node bound caching (for SNLite at least...)

Created by: zeffii

• static_caching (basic, one per node)
• responsive_caching

  • some kind of combination tuple as hashmap key:

       component_id = self.node_id
       component_function_text = hash(inspect.getsource(function_to_use))
       component_variables_hash = hash(str(variables))
    
       cache_key = (component_id, component_function_text, component_variables_hash)

  • so if the cache is invalidated if

    • user has code changes to the input function
    • user changes input variables

  • considerations:

    • do i want automatic cache culling?
      • include function name as part of the hash key so as to make it more convenient to delete cache's where keys contains the first two components
• make it a mixin
  • altho, because not all scripts will use this maybe having it as a default mixin is not a good idea...

and see how that goes