def execute(force=false)
      return false if executed? && !force
      evaluate_recipes
      transaction = apply
    rescue Exception => e
      false
    else
      not transaction.any_failed?
    ensure
      @executed = true
    end
def execute(force=false)
      return false if executed? && !force
      evaluate_recipes
      transaction = apply
    rescue Exception => e
      false
    else
      not transaction.any_failed?
    ensure
      @executed = true
    end
Execute this manifest, applying all resources defined. Execute returns
 true if successfull, and false if unsucessfull. By default, this
 will only execute a manifest that has not already been executed?.
 The +force+ argument, if true, removes this check.