Update dippl to reflect new interfaces; integrate new editor + viz

[null-a]

Once #86, #246, #268 are done.

[stuhlmueller]

I've started porting this over. I'll use this issue to keep track of dependencies and todos that come up:

• Fix resumeTrampoline is not a function in draw.js
• Provide wpEditor print for printing to results box from Javascript
• Use distribution types from Javascript
• Make webppl-editor compatible with latest dev version (including error handling)
• Make webppl-viz compatible with new distribution interface.
• Merge error handling
• Update chapters:
  • Chapter 1
  • Chapter 2
  • Chapter 3
  • Chapter 4
  • Chapter 5: Particle Filtering (requires something like wpEditor.print; see above)
  • Chapter 6: MCMC
  • Examples: Pragmatics
  • Examples: Semantic parsing
  • Examples: Computer vision (requires resumeTrampoline fix above)
  • Examples: Pragmatics with compositional semantics