Autocomplete with onBlur event

[vitorstick]

[ ] bug report => Search github for a similar issue or PR before submitting
[X] feature request => Please check if request is not on the roadmap already https://github.com/primefaces/primeng/wiki/Roadmap
[ ] support request => Please do not submit support request here, instead see http://forum.primefaces.org/viewforum.php?f=35

Adding onBlur event to Autocomplete

Expected behavior
Get the moment when autocomplete is not selected anymore

What is the motivation / use case for changing the behavior?
When user only fills with text and don't select none of the options displayed, we chose the most probable for him on them method called by the onBlur

[stephanie-dm]

This looks like a duplicate of #1387 and possibly also #617