added diffviewer sketch
add arrows to parent diff titles
Add destroy method to pvjs public instance
Allow putting custom pathways into diff demo
Expose get pan and zoom through public instance
Sync first pathway with second in diff view
replace get/set attribute with style in selector
Sync both diff pathways in demo
Do not display typeahead on diff pathways
Sort diff groups alphabetically by title
Use a more proeminent orange for removed nodes in diff viewer
highlight diff groups
refactor diff's groups highlighing
Display titles instead of ids for interactions endpoints
Working on integrating gpml to json, not yet functional
it's working with new gpml2json code, although the edges are not perfect yet
Merge branch 'diff' into newjson

Conflicts:
	src/js/pathvisiojs.js
Use unminified version of pathvisiojs in demo
Adjust highlighter to newjson
Adjust diff viewer to newjson