MAKE-STRING
===========

syntax: (make-string <size>
               [:initial-element <initial-element>])

This function produces a string with the length
<size>, which is filled with space characters.
Optionally it can be filled with other characters!

example:       >(make-string 3)
               "   "
               >(make-string 4 :initial-element #\x)
               "xxxx"