Synopsis:
   $strcmp(str1 str2)

Technical:
   Str1 and str2 are compare alphanumerically letter by letter until a
   difference is found. The difference is returned as a numerical value:
   negative for less than, 0 for equal, and positive for greater than.
 
Practical:
   Pay attention to the fact that when they are equal it will return 0.
   Also note that if either string is null a null is returned (is this a
   bug).
   
Returns:
  < -1 : if str1 is less than str2
     0 : if str1 is exactly equal to str2
  > +1 : if str1 is greater than str2

Examples:
   $strcmp("hello" "hell")	returns 111
   $strcmp("hello" "hello")	returns 0
   $strcmp("hell" "hello")	returns -111
   $strcmp("hell" "")		returns nothing

