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/frc971/control_loops/index/index.cc b/frc971/control_loops/index/index.cc
index 0e5270a..90eaf6e 100644
--- a/frc971/control_loops/index/index.cc
+++ b/frc971/control_loops/index/index.cc
@@ -4,8 +4,6 @@
 
 #include <algorithm>
 
-#include "aos/aos_core.h"
-
 #include "aos/common/control_loop/control_loops.q.h"
 #include "aos/common/logging/logging.h"
 #include "aos/common/inttypes.h"
diff --git a/frc971/control_loops/index/index.gyp b/frc971/control_loops/index/index.gyp
index f61da8c..9cfb019 100644
--- a/frc971/control_loops/index/index.gyp
+++ b/frc971/control_loops/index/index.gyp
@@ -8,12 +8,10 @@
         'header_path': 'frc971/control_loops/index',
       },
       'dependencies': [
-        '<(AOS)/build/aos.gyp:libaos',
         '<(AOS)/common/common.gyp:control_loop_queues',
         '<(AOS)/common/common.gyp:queues',
       ],
       'export_dependent_settings': [
-        '<(AOS)/build/aos.gyp:libaos',
         '<(AOS)/common/common.gyp:control_loop_queues',
         '<(AOS)/common/common.gyp:queues',
       ],
@@ -27,7 +25,6 @@
         'index_motor_plant.cc',
       ],
       'dependencies': [
-        '<(AOS)/build/aos.gyp:libaos',
         'index_loop',
         '<(AOS)/common/common.gyp:controls',
         '<(DEPTH)/frc971/frc971.gyp:common',
@@ -49,7 +46,6 @@
       ],
       'dependencies': [
         '<(EXTERNALS):gtest',
-        '<(AOS)/build/aos.gyp:libaos',
         'index_loop',
         'index_lib',
         '<(AOS)/common/common.gyp:queue_testutils',
diff --git a/frc971/control_loops/index/index_main.cc b/frc971/control_loops/index/index_main.cc
index 9ca3290..c542268 100644
--- a/frc971/control_loops/index/index_main.cc
+++ b/frc971/control_loops/index/index_main.cc
@@ -1,6 +1,6 @@
 #include "frc971/control_loops/index/index.h"
 
-#include "aos/aos_core.h"
+#include "aos/atom_code/init.h"
 
 int main() {
   ::aos::Init();