Store if paper has references, only follow paper with references
Merge pull request #2 from citenet/visualization

first vis
Add graph visualization

render using "dot -Tpng graph.dot > graph.png"
doing a better job prioritizing targets, by also including depth as a criterium
Filtering out nodes that have low global citation scores, have no references and no citations
Merge branch 'post-filter-devel'
cleanup and use real min/max values
let's spin it baby