Add ability to set pull direction in PinAlarms

[Levtastic]

Currently when creating a PinAlarm object you can only set the pull to be opposite what you are alarming on. This makes it impossible to wake on a connection from a pin being severed.

Example:
You have a pin that connects to ground, where this connection can be broken.
Detecting this connection being made is possible because you can pull up while floating, and wake on the signal going down, signalling that you just connected to ground.
However, detecting this connection being broken isn't possible, because you begin grounded, and you want to pull up while also waking on the signal successfully going up when the ground connection is severed. The current PinAlarm object creation doesn't allow you to both pull up and wake on the signal successfully going up, making this impossible.

[bill88t]

Note: You can externally pull up, then plug a wire to ground.
Then when the ground wire is severed, it will trigger a "going up" alarm.