#2 report function getel() doesn't work as specified

[Tom Morris]

This function only worked for index values from 1 to
the size of the list, but the C documentation says that
0 will return the last element in the list and -1 the
one before that and so on.

The C implementation shows that any negative number
that wraps around more than once is illegal. The
implementation also appears, however, to do automatic
list growing if a caller requests an element with an
index beyond the end of the list.

Support for 0 and negative indexes has been added, but
support for indexes greater than the size of the list
still needs to be fixed.