Before this commit, portal was a Component, now is a directive.
This commit also clean some unused code, and fix an issue on the clean
optimization when a portal is found in a condition or a loop.
Before this commit, there were situations where the reference numbers
were not properly set, which caused the blocks generated to crash
because the algorithm could not get correct references.
Synthetic handler is a sort of event delegation that allows placing
only one listener on the document to improve performance. It is an opt-in option.
Native listener places the listener on the node itself.
Géry Debongnie