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/gyro_interface.h b/frc971/wpilib/gyro_interface.h
index cd734a9..3568a47 100644
--- a/frc971/wpilib/gyro_interface.h
+++ b/frc971/wpilib/gyro_interface.h
@@ -3,7 +3,7 @@
 
 #include <memory>
 
-#include "SPI.h"
+#include "frc971/wpilib/ahal/SPI.h"
 #undef ERROR
 
 namespace frc971 {
@@ -47,7 +47,7 @@
   uint32_t GetReading();
 
  private:
-  ::std::unique_ptr<SPI> gyro_;
+  ::std::unique_ptr<frc::SPI> gyro_;
 };
 
 }  // namespace wpilib