Added ahal

This is a formatted copy of WPILib's default user-visible C++ API, with
a bit of completely unnecessary functionality stripped out. Most of the
stripping so far is only related to weird threading decisions.

Change-Id: Icbfd949b48cd115561862cb909bcc572aba0e753
diff --git a/frc971/wpilib/encoder_and_potentiometer.cc b/frc971/wpilib/encoder_and_potentiometer.cc
index 379a29f..8fe8c25 100644
--- a/frc971/wpilib/encoder_and_potentiometer.cc
+++ b/frc971/wpilib/encoder_and_potentiometer.cc
@@ -37,11 +37,12 @@
 
   ::aos::SetCurrentThreadRealtimePriority(priority_);
 
-  InterruptableSensorBase::WaitResult result = InterruptableSensorBase::kBoth;
+  frc::InterruptableSensorBase::WaitResult result =
+      frc::InterruptableSensorBase::kBoth;
   while (run_) {
     result = index_->WaitForInterrupt(
-        0.1, result != InterruptableSensorBase::kTimeout);
-    if (result == InterruptableSensorBase::kTimeout) {
+        0.1, result != frc::InterruptableSensorBase::kTimeout);
+    if (result == frc::InterruptableSensorBase::kTimeout) {
       continue;
     }