…, the module was not registering any old node classes during reload event

…ing event (F8, script.reload), some functions had ridiculous logic, mistakes in function descriptions

…ees before 2018. To keep the code does not have sense because in 2018 backward compatibility with old node trees was broken. Now nodes should have `load_file_update` method if they want to fix something upon loading a file.

…e to do this but it will let to keep our update system simpler.

…gers

…r this calls as really fragile solution to update nodes content after loading a file even if it looks like proper approach. It will let to keep our update system simpler and don't think how this should be handled during importing JSON files.

…gister

# Conflicts:
#	core/__init__.py
#	core/handlers.py
#	old_nodes/__init__.py

… handling_nodes.py. During initialization (second time) they was tried to be registered two times