Add support for not automatically starting applications

There are cases where we want a debug application (web server is a
reasonable example) which doesn't start up automatically, but can be
started on demand.  Add an "autostart" to the application config entry
to signal this.

Change-Id: Id88ec8a164f42adb73902e2f0ba30c9d1ecea5c9
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>
diff --git a/aos/starter/starterd_lib.h b/aos/starter/starterd_lib.h
index 38a11d6..cd4b40a 100644
--- a/aos/starter/starterd_lib.h
+++ b/aos/starter/starterd_lib.h
@@ -95,6 +95,8 @@
       const flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>>
           &args);
 
+  bool autostart() const { return autostart_; }
+
  private:
   void DoStart();
 
@@ -124,6 +126,7 @@
   aos::monotonic_clock::time_point start_time_, exit_time_;
   bool queue_restart_ = false;
   bool terminating_ = false;
+  bool autostart_ = true;
 
   aos::starter::State status_ = aos::starter::State::STOPPED;
   aos::starter::LastStopReason stop_reason_ =