Remove args and result
Introduce Event object and refactor Conditional and EventSlot to use it
Use Event in Method and Attribute
Removed "on" Method event and use relative import
simplify imports
can remove all passed events and listeners
add method trigger_event, normalize event data and permit clean of slot
Use event.call to set result and add func_defaults property
add CI requirement, buidl and gitignore
Make event creation in one place and set default in assert_is_set