Returns an array of items built from the passed arguments
with the following rules:
If an argument is a scalar value then the argument itself is appended to the result.
If an argument is an array then each contained item is appended to the result.
If an argument is a hash then each contained value is appended to the result.
A simple example of usage is to merge N arrays into a new one.
(Please note that for merging one array into another the
array concatenation operator is more efficient).
