Conception refactor

- DOM methods are no longer database values, they don't carry any value
	in database sense and it's fine to use them as regular defined
	properties. This way we can also use functions provided by other API's
	(like dom-ext)
- Input objects are also event emitters. Introduced events:
	- `change:changed` fired when 'changed' status on input changes
		(changed status is true when value is different from saved database
		value)
	- `change:valid` fired when validity of inputted value changes
- Generated control types are now grouped in _controls folder
- Use getter/setter value instead of get/set methods
- Rename InputRow to more generic FieldsetItem