made it so that AnalogTriggerOutput actually works as an InterruptableSensorBase

Before, it just had empty methods with TODOs on them. These changes have been
tested, and the only thing is that AnalogTriggerOutput::Type::k*Pulse don't seem
to work.

git-svn-id: https://robotics.mvla.net/svn/frc971/2013/trunk/src@4189 f308d9b7-e957-4cde-b6ac-9a88185e7312
7 files changed