Clean up include paths

Remove runtime/globals.h and make clients point to the right globals.h
(libartbase/base/globals.h).  Also make within-libartbase includes
relative rather than using base/, etc.

Bug: 22322814
Test: make -j 40 checkbuild
Change-Id: I99de63fc851d48946ab401e2369de944419041c7
diff --git a/runtime/obj_ptr.h b/runtime/obj_ptr.h
index 14fdba3..e421d87 100644
--- a/runtime/obj_ptr.h
+++ b/runtime/obj_ptr.h
@@ -20,9 +20,9 @@
 #include <ostream>
 #include <type_traits>
 
+#include "base/globals.h"
 #include "base/macros.h"
 #include "base/mutex.h"  // For Locks::mutator_lock_.
-#include "globals.h"
 
 namespace art {