next implemented, but untested.

Requies the notion of current to be implemented.
notion of current applied to first and last

need to apply current to next
basic next tested

need to add cases where current is NULL or next when the last node
is current.
next fully implemented

need to work on prev
prev implemented

time to start work on at()
at() implemented

need to implement destructor then start tackling TODO's
Greater than fixed.

Took out all references to >