BUG: handle file/dir creation in make_stores
Add close method
API: add frame arg to add_to_panel*

also handle wrinting all in one place.
API: Make panel_store optional.

Also dont need keys to make_panel
more notes for presnting
TST: cleanup and new tests
ENH: Add getitem. more docs
CLN/REF: be explicit about ids. get wp from func
BUG: select node for close.

BUG: prepend with 'm' to write

BUG: fix api on add_to_panel