[WIP] Rejig output format for nodes 

PREVIOUS
{
 nodes: [1,2]
 page: 1, 
 span: [6333,6539],
 sentence: “blah blaj” 
 label: 1
}

CURRENT
{
 nodes: [{index: 1, range: [141, 414],  span: [151, 412], page: 1}]
 sentence: “blah blaj” 
 label: 1
}
[WIP] Make viewer accept new nodes format
Within node and between page annotations
Merge branch 'master' of github.com:joelkuiper/spa

* 'master' of github.com:joelkuiper/spa:
  adding pickled pos tagger
  initial attempt at including sample size prediction
Revert "initial attempt at including sample size prediction"

This reverts commit f108ac15ebf2e90b950223c3355426d68a623f59.