Change PathData to a constructor and document the corresponding class accordingly.
Move page advance and data transmission code from showButton() into PathData.send().
Create and document Button class (to replace showButton()).
Add grunt.  Add QUnit.  Refactor core.js so that the module is an object, not a function.  The map and drawingManager variables are made available to the module using the init() method.
Add @memberOf tags to comments so that jsDoc3 can parse definitions inside the function closure.
Change module name from 'dowsing-js' to 'spatialsurvey'.
Refactor PathData.send() and PathData.load() to use sessionStorage.  Add spatialsurvey.advance() method.
Refactor mapHelper.Line() and add tests for closestPointOnPolyline.
Add spatialsurvey.advance() call to PathData.send().  Register rightClickButton automatically on polylinecomplete.