Merge pull request #420 from MDCox/programmaticStyles

Fixes to Programmatic styles
Merge pull request #422 from MDCox/clustering

Clustering
Merge branch 'release-0.3' of https://github.com/GraphAlchemist/Alchemy into v0.3
NodeType tag applied uniformly
Node/Edge toggles work with new data model
Toggle with multiple edges between the same node