added PropSource.asMap conveniences, rename UberPropSet to LivePropSet - more reflects the name of the module and easy to remember for the thing that will likely be the most generally useful (and used) class, where as DynamicProp. Alias DynamicPropsSets to PropsLive for similar reasons. These are located in the base package 'propslive', to best represent the simplest and target common usage case.