cleaned up LOTS of build-related stuff

There were a lot of things that were relying on transitive #include
and/or gyp dependencies that I fixed.
I also got rid of all references to libaos and a lot of references to
aos/aos_core.h and its build target.
This in preparation for removing libaos completely.
diff --git a/aos/atom_code/camera/Reader.cpp b/aos/atom_code/camera/Reader.cpp
index 2c07332..b9dc36d 100644
--- a/aos/atom_code/camera/Reader.cpp
+++ b/aos/atom_code/camera/Reader.cpp
@@ -13,9 +13,10 @@
 #include <string>
 #include <inttypes.h>
 
-#include "aos/aos_core.h"
+#include "aos/atom_code/init.h"
 #include "aos/atom_code/camera/V4L2.h"
 #include "aos/atom_code/camera/Buffers.h"
+#include "aos/common/logging/logging.h"
 
 #define CLEAR(x) memset(&(x), 0, sizeof(x))
 
@@ -407,5 +408,9 @@
 } // namespace camera
 } // namespace aos
 
-AOS_RUN_NRT(aos::camera::Reader)
-
+int main() {
+  ::aos::InitNRT();
+  ::aos::camera::Reader reader;
+  reader.Run();
+  ::aos::Cleanup();
+}