Merge pull request #36 from mlippert/widget-refactor

Changed imageviewer lite behavior
Hotspot "type" on sketches

I like this implementation pretty well.  The hotspot type adds a class that makes all sketches transparent until highlighted, at which point they are 40% opaque.  Any sketch object can be a hotspot, but you have to fill them if you want them to be clickable over their whole area.  The fill implementation is by shape (group) but should probably be item by item. fill: 'White' is best for hotspots I think.
Removed special lit class from hexagons

class was unecessary after changes, and was causing gray highlighting which
was different and wrong.
Paths in sketch tool

A literal SVG path can be specified as data for the sketch tool.  I could have done this using
xy data in an identical fashion to line graphs, but this doesn't help me get the freeform shapes I need to highlight areas on an image for hotspots.  I can get the svg directly out of illustrator, so I used that instead. Note that it doesn't get scaled, so is somewhat imperfect.