Returns all of haystack from the first occurrence of needle to the end. needle and haystack are examined in a case-insensitive manner.
If needle is not found, returns FALSE.
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
Megjegyzés: Ez a függvény "binary-safe", azaz helyesen kezeli a 127-es ASCII kód feletti karaktereket is.