Add User#views_hash
Destroy views when they are not longer shared with a user

unless that user has that item shared with it somewhere else
Update views to use views_hash
Get some more of sharing working
Add User#nested_items (aka better_hash)
Update can_edit? to user nested_items
Remove view creating hooks
Add Item#can_view? and tests
Change items#index to rely on nested_items
Bring items#show back online
Fix collapsing and take out the trash
Fix items#create