This function implements a sort algorithm that orders
alphanumeric strings in the way a human being would. This is
described as a "natural ordering".
natcasesort() is a case
insensitive version of natsort(). See natsort()
for an example of the difference between this algorithm and
the regular computer string sorting algorithms.
For more information see: Martin Pool's Natural Order
String Comparison page.
See also sort(), natsort(),
strnatcmp(), and
strnatcasecmp().