mass_contact 7.x-1.0-alpha3

Fixed this: #1314372: Undefined property error.. mail being delivered to only a few members of the site.

Here are the details:

• There was a bug in the opt out code that only actually worked some times.
• While working through fixing that, I realized I had a logic flaw in the database query I was using to select recipients, such that all users in the database would be polled, when that was unnecessary.
• While fixing that, I realized the way I was doing categories and opt outs, in general, both made it hard to separate the category logic later, and made it such that opting out wouldn't always work the way people might expect it.
• While fixing that, I realized I could combine most of the recipient list selection code and opt out code into a single concise function that should reduce the time it takes to create the recipient list.

So, I revamped how I handle selecting recipients from the selected categories and removing recipients from the opt outs, hopefully resulting in better logic and code. We'll see.