updated after further conversations with bill, still a work in progress.

 -  added a 'template-content' conditional to handlebars to return an alternate AST
 -  parse the 'content' AST tag in Template and return the compiled 'contentNodes'
 -  updated Widget to parse the 'contentNodes' appropriately for 'select' nodes (and for 'universal' selector nodes)
 -  updated the example test to show declarative and programmatic usage