odds and ends clean up
hn.hbs: switch to view.content.nodeParent.isHash instead of view.content.hasKey; completely refactor ContentField, now is abstract class; have keyfield < contentfield and valfield < contentfield. refactor dC.commitChanges into commitKey and commitVal
update nodeIdx to be a one way computed property
completely restructure humon_node to use blocky span; restyle; add ProxyField and IdxField to ContentField; update dC jquery selectors
add placeholder functionality for key and val fields