Merge branch 'develop'

* develop: (31 commits)
  Display models in the scene using XTK
  Configure MRML "scene" representation from the XML/MRML file
  Support for parsing the MRML file inside the MRB
  Ignore
  Deal with binary VTK files by converting to ASCII
  Convert a binary VTK file to ASCII
  Start at documentation.
  Include X so we can debug XTK
  Beginnings of an XTK display
  Simple XTK display
  Reworked gulp, included documentation generator
  Save compiled JavaScript into the build/js directory
  Added helper function for testing purposes
  Removing stray comments
  Make our build a bit smoother
  Missing files
  Reorganization of source code
  Removed a few unused packages
  Makefile support for test and dev targets
  Small reformat of testem.json
  ...
Added more packages
Changed web ui to include drag-n-drop
Merge branch 'feature/drag_n_drop' into develop

* feature/drag_n_drop:
  Changed web ui to include drag-n-drop
  Added more packages