add iterators to hashtable, skiplist, and list
drwxr-xr-x - datatype
drwxr-xr-x - include
-rw-r--r-- 1905 license.txt
-rw-r--r-- 3207 makefile
drwxr-xr-x - map
drwxr-xr-x - runtime
drwxr-xr-x - test
-rw-r--r-- 884 todo
drwxr-xr-x - txn