Rebuilding Interact.jl with WebIO.jl

Interactive data exploration is an increasingly important component of data science. Interact.jl and Escher.jl are good libraries that have the potential to be extremely powerful for these tasks, but currently Interact only supports IJulia and Escher suffers some stability issues. WebIO.jl looks to be a promising path forward for building web based components that are created by or interface with Julia. Rebuilding Interact.jl on top of WebIO.jl will bring Interact beyond IJulia, to the Atom/Juno IDE and to desktop apps with Electron/Blink.jl. Additionally it should enable Escher.jl to reuse much of Interact, which will likely reduce Escher’s size and complexity significantly, increasing its stability. Furthermore, by removing its dependence on Jupyter and IPywidgets, Interact will gain flexibility to produce more complex UIs which intermix displayed data such as plots, and UI controls. Finally, I plan to add some automated UI testing which hopefully will assist in improving the stability of not just Interact and Escher, but potentially IJulia, Juno, and Blink as well.