don't move cards if new list or board is identical to origin
only update changed values
Merge pull request #37 from benzimmer/better-card-moving

Don't move cards if target list or board is identical to origin
Merge pull request #38 from benzimmer/only-put-changed-attributes

Only 'put' changed attributes
add list position to registered attributes
Merge pull request #40 from rossta/list_position

Add list position to registered attributes