Synopsis:
   $jot(<start> <stop>)

Technical:
   This script is used to obtain a series of integers, from the first input
   to the second.  Negative numbers are permitted, and the series may be
   ascending or descending.

Practical:
   This function is used to generate a number range.  One popular use for
   this is in conjunction with $chr(), allowing a range of ascii characters
   to be returned (which then might be stripped from another string, etc.).

Returns:
   * number range from start to stop
   * if less than 2 arguments, empty string
   * if more than 2 arguments, first argument
   * if non-digits entered, 0 (zero)

Examples:
   $jot(2 6)             returns "2 3 4 5 6"
   $jot(3 -2)            returns "3 2 1 0 -1 -2"
   $jot(4)               returns ""  (empty string)
   $jot(4 6 8)           returns "4"
   $jot(a 4)             returns "0"

See Also:
   chr(6); isdigit(6)