The Digital and Analog headers (and the implementations, but that will
be moved over later) are just too big and congested. This splits those
headers, and then changes the few things that needed to be changed in
WPILib to get the code working again. No function changes were made in
this commit.
As the notifierMutex is unlocked while the callback is being called in
alarmCallback(), it's possible for next to be invalidated due to a
cleanNotifier() call. Now, instead of deleting the notifier immediately,
add it to a freelist to be cleaned up at the tail end of alarmCallback.
Rename the following folders:
hal/lib/Athena -> hal/lib/athena
hal/lib/Desktop -> hal/lib/sim
hal/lib/Shared -> hal/lib/shared
wpilibc/Athena -> wpilibc/athena
wpilibc/simulation -> wpilibc/sim
Windows users may need to run gradlew clean after updating.
