Feature/add window example

[jeffreycwitt]

we don't actually need to pull this in, but I extended the working ui example to not only adde a manifest, but to add a window, and navigate forward and backwards.

In the process, I discovered the need to indicate the index of the image annotated on the canvas. If we don't want to hard code this to the 0 index position, I suggest adding an imageIndex to the default properties of the addWindow actions. I made that addition in this pull request.

Screen shot

[sdellis]

@jeffreycwitt That's a good call to add image index in as one of the values to the redux default state. As much as I like your additions to the UI, I'm not sure we want to add too much complexity to this PoC stage. Easier to track down bugs when there's less code. At any rate, I'll leave that up to @aeschylus .

[jeffreycwitt]

@sdellis oh I definitely agree. I didn't really mean for it to be pulled in. I just wanted to make another example.
You can close it.
jw