Renamed {elmdoc.dat => elm_doc.json}
Updated help system

* Show full documentation by selecting the symbol and pressing Cmd+Ctrl+/ (Mac) or Ctrl+Alt+/ (Windows/Linux)
* Only check for open imports (TODO: detect qualified references and open imports of specific names)
* Use the documentation JSON from http://elm-lang.org/docs.json
Merge branch 'new-docs'

Conflicts:
	elm_reference.py