creating tree interface
tree def
list subscript access
tree iterator
iterator file created
Merge branch 'list'
Merge branch 'iterator'
i_iterator -> i_list_iterator
common list iterator
list_iterator is compliant with general intf
merge resolved
incr/decr operators for iterator implemented
tree interface
node as a separate interface
some node problems
node changes
hash table test failure
FAULT IN HASH TABLE
circular list
shitty approach to circular list -> must be fixed by inheritance