Initiate plan: add 2 scaffolds and 3 models:

1. plan, plan_set
2. store_fixture, deployment, position
extend ActiveRecord::Relation to_hash/to_hierarchy
fixed schema: plan_sets, etc
initialize plan editor
plan editor: fixture layout done
plan editor: setup work frame
rename price_level to price_zone
plan editor: load/store finished
plan editor: add toolbar command, overflow detect
add toolbar-select: switch model store
add plan forms: summary, copy-to, publish
js: add messageBox, openDialog; impl copy-to, auto-position

refines product table grid, now equal spacing
fix overflow div error show bug, give a unique id
fixed positionRemove bug; refactor :_do, model/update

1. fixed positionRemove bug: js error
2. add id to all forms
3. complete publish form, add :finish_state
4. refactor :_do, model update;
5. revise to_hash helper, etc to accept method of model
6. fixed auto_position bug: slot order
plan: add position gap/divider dialogs
add showing colors menu
implements leading-gap, dividers, showing-colors
plan: finish layout-editor

1. refine CmdUI
2. add ProductTable
rebase: modify schema,fixtures,tests, test passed
Merge branch 'feature/add-plan' into develop