Removing odbc::%cstring-into-vector -- unused and unreliable.

Removing odbc::%cstring-into-vector -- unused and unreliable.

The idea of the function was to copy out of c string memory into a
lisp string a byte at a time, converting to lisp characters as we go.

However:
 * this doesn't work with multibyte charsets
 * the underlying deref-array funcall would sometimes pull the entire
   array into lisp to then get at the single element-- for each element.
 * set elements in the lisp array using schar but there's no guarantee
   that the lisp array is a simple-string. Newer SBCL's err on this.