Centralize creation of "zoom" buttons in Ui.js
Configure require before loading app

When the app javascript files are loaded and parsed, they may
use the require function, which, if not configured prior will try
to load resources fron incorrect locations
Legend can resize, move and re-flow

Reformat the markup generated by the Legend dijit to allow a multi
column reflow when the legend space is enlarged.  Adds support for
resizing and dragging using the existing dojo framework.  I found the
dojo tools to be much weaker than jquery UI, but as this is already a
heavily library-dependent app already, and dojo comes pre-loaded
with the ESRI jsapi, I chose to live with what it can do rather than
add a new dependency.
Remove unused variables
Focus layers.json for testing

* Simplify layers.json
* Add error cases
* Allow comments in JSON (strip before parsing)
* Add comments to layers.json
Merge pull request #178 from RickMohr/layers-json-for-testing

Layer selector: Cleanup, and focus layers.json for testing, and
Merge pull request #177 from mmcfarland/topic/legend-reflow-final

Legend Relow