Discuss Singleton, Factory, and Builder (DPiR Ch 12-14)

We're continuing our discussion of design patterns; next up are Singleton, Factory, and Builder.

Singleton has often been criticized, and Factory + Builder go together, so per Dan's suggestion, we'll be mostly focusing on Factory and Builder next time. (Essentially, you can read Singleton at your option; we won't discuss it a ton.)

The venue is the same as last time: Google Hangouts. If you're new, please make sure that you add either Benjamin Oakes or Jonathan E. Magen on Google+ letting us know to put you in the newhaven.rb circle so that you can access the Google+ Hangout. Also, please try to join 5ish minutes prior to 12pm in case you need to troubleshoot something.