#217 Fixed radio selects.

The radio selects weren't changing their respective state variables upon being clicked. I'm not entirely sure if valueLink works for radio selects so I put the onChange handler in, but there may be a more concise way of adjusting the state variable upon a change.
For event handlers, let's make the convention such that `onFoo` maps to `_handleFoo`. In the case of name collisions like this one, we can do `_handleProgramTypeChange` and `_handleLocationChange`.