added navigation tools

Hopefully I did this fork/PR correctly. One thing I could not figure out is to upload images. Images came from https://developers.arcgis.com/javascript/jssamples/toolbar_navigation.html This will likely break without them. The button images look funky anyway, maybe use text links instead like you did in the Directions widget? 

Feel free to change the name of each file, it's not really a toolbar, maybe NavigationTools is a better choice.

I know there was some discussion about the addition of nav tools in earlier posts scattered about. These are requested at my organization so just posting for anyone to use even if not accepted into CMV by default.

Original code came from ESRI sample, I take no credit here, just hacked away at someone elses work.