[Code Cleanup] Move accounting.[ch] to decoder

Bit accounting is really a decoder thing

BUG=aomedia:450

Change-Id: Ib0229064caa98f742e2df08fd79c0451b0d8c09e
diff --git a/examples/analyzer.cc b/examples/analyzer.cc
index 752f1bd..591aaf2 100644
--- a/examples/analyzer.cc
+++ b/examples/analyzer.cc
@@ -16,7 +16,7 @@
 #include "./video_reader.h"
 #include "aom/aom_decoder.h"
 #include "aom/aomdx.h"
-#include "av1/common/accounting.h"
+#include "av1/decoder/accounting.h"
 #include "av1/common/onyxc_int.h"
 #include "av1/decoder/inspection.h"