First semi-functioning new subcommand parsing

Help is probably totally hosed, but we're getting there.

Refs #96
default to normal mode in tests

Also don't send options up to the parent in normal mode
I think more proper options for nested subcommands works

* Copied old todo app to todo_legacy and moved tests
* Made *new* todo app use the new "normal" subcommand option parsing
* avoid navigating to topmost_ancestors unless needed

Refs #96
Fix _doc command to use correct stragegy

For #96