Import new SVG graph JavaScript code.
Update Pig visualizer to use latest SVG graph code.
Merge pull request #35 from davidzchen/cleanup-visualizers

Pig Visualizer uses new SVG graph code
Display features and aliases on Pig visualizer nodes.
Remove unused flow-loader.js
Add styling for Pig Visualizer graph.
Merge pull request #36 from davidzchen/cleanup-visualizers

Improve Pig Visualizer graph
Fixed compiler warnings, mainly involving unused imports and deprecated methods
Fixed several JavaScript errors: moved bootstrap import after jquery import, added null check
Fix so when there's an error on save, we still preserve the user's edits
Added "Save" button to top of Reportal edit page, adjusted page template to use 2-space indentation
Changed "Run" button into a "Save and Run" button