has a bug in .del()
BROKEN ALGORITHM not Storage
test to prove brokeness
testing & debugging
WORKING minus releasing handles
fixed error is use of parent.add. line 641
tweeked command line stuff
removed dorky printf debug
Fixed .remove() api.
Now it is like leaf.remove api; it takes only a key and returns a deleted
child value (a handle). aka `hdl = br.remove(key)`.
changed constructor argument to #ms of delay; -1 for nodelay
implemented choice of MemStore or TrivialStore & some output tweaks
several changes
- removed alot of printf-debugging aka `console.warn` messages
- changed api from passing (newHdls, oldHlds) around to just deadHdls
- made .cleanHandles() work. problem was some .storeSimplePath calles would
  not progress to root. Put .cleanHandles() call in where .storeSimplePath
  gives up on walking up the path chain.
updated the default TrivialStore cuz of api change
updated tests given api changes