Change is_long() to be an alias of is_integer()

@@ See internals: news.php.net/php.internals/79639
@@ Manual will be updated so that is_int() will be an alias of is_integer()
@@ I picked integer over int for consitentcy as we do not use str instead of string either
NEWS
Change back to use is_int() as function instead of is_integer(), as per Jan Tvrdík's request @github