Refactor w/ control base class. Controls self aware of external changes to layer state. Better docs. Layer controls accept layer id as well as layer object. Minor CSS tweaks. Add all on/off menu items for dynamic layers with sublayers.
Turn all sublayers on/off affecting other layers fixed.
Add methods to turn all layers on/off.
Add metadataUrl control option.
Merge pull request #240 from cmv/LayerControl-1.3.1-patch

LayerControl 1.3.1 patch
Merge branch 'develop' into feature/dbootstrap-separate-css-from-js

Conflicts:
	viewer/index.html