Fullscreen updates.

1. Move fullscreen button to lower right.
2. Added new SVG images to indicate which action the button will perform.
3. Themed the buttons so they match the rest of viewer.

This isn't quite ready to be merged, but I wanted to get some feedback.  I'm not much for design, so I assume @emackey may want to tweak the SVGs.

Also, I'm considering pulling out this code into it's own widget, but I wasn't sure if that was overkill.  I'm leaning towards doing it (and also de-dojo-fying it in the process).  It will go along nicely with other things we're doing elsewhere (like the cesium-widget branch).
Break fullscreen button into it's own minimalistic widget.
Create FullscreenViewModel and bind it to FullscreenWidget via knockout.
Minor fixes after latest refactoring.
Fix casing.
Fix use of `knockout.applyBindings`

We should always be passing applyBindings the element we are binding
too, this avoid collisions when having multiple widgets with the
same bindings.
Merge branch 'master' into fullScreen

Conflicts:
	Source/Widgets/Dojo/CesiumViewerWidget.css
Fix merge.
Changes based on review.
More changes after review.
More changes after review.

1. Optimize SVGs (they are much smaller now).
2. Change constructors to take the element to fullscreen.
3. Tweak some documentation.
Merge pull request #534 from AnalyticalGraphicsInc/fullScreen

Fullscreen updates.