ART: Clean up thread.h and thread_list.h

Remove dependency on stack.h and gc_root.h. Remove unused object
callbacks include. Factor out ManagedStack into its own set of files.
Fix up users of transitive includes.

Test: m test-art-host
Change-Id: I01286c43d8c7710948c161b1348faabb05922e59
diff --git a/runtime/interpreter/unstarted_runtime.cc b/runtime/interpreter/unstarted_runtime.cc
index 96934bc..152cce4 100644
--- a/runtime/interpreter/unstarted_runtime.cc
+++ b/runtime/interpreter/unstarted_runtime.cc
@@ -50,7 +50,7 @@
 #include "mirror/string-inl.h"
 #include "nth_caller_visitor.h"
 #include "reflection.h"
-#include "thread.h"
+#include "thread-inl.h"
 #include "transaction.h"
 #include "well_known_classes.h"
 #include "zip_archive.h"