Convert aos over to flatbuffers

Everything builds, and all the tests pass.  I suspect that some entries
are missing from the config files, but those will be found pretty
quickly on startup.

There is no logging or live introspection of queue messages.

Change-Id: I496ee01ed68f202c7851bed7e8786cee30df29f5
diff --git a/frc971/wpilib/loop_output_handler_test.fbs b/frc971/wpilib/loop_output_handler_test.fbs
new file mode 100644
index 0000000..6cb2cf1
--- /dev/null
+++ b/frc971/wpilib/loop_output_handler_test.fbs
@@ -0,0 +1,6 @@
+namespace frc971.wpilib;
+
+// Test output message.
+table LoopOutputHandlerTestOutput {
+  voltage:double;
+}