Tidy up logging.

Move gVerboseMethods to CompilerOptions. Now "--verbose-methods=" option to
dex2oat rather than runtime argument "-verbose-methods:".
Move ToStr and Dumpable out of logging.h, move LogMessageData into logging.cc
except for a forward declaration.
Remove ConstDumpable as Dump methods are all const (and make this so if not
currently true).
Make LogSeverity an enum and improve compile time assertions and type checking.
Remove log_severity.h that's only used in logging.h.
With system headers gone from logging.h, go add to .cc files missing system
header includes.
Also, make operator new in ValueObject private for compile time instantiation
checking.

Change-Id: I3228f614500ccc9b14b49c72b9821c8b0db3d641
diff --git a/runtime/signal_catcher.cc b/runtime/signal_catcher.cc
index 336340e..6d67836 100644
--- a/runtime/signal_catcher.cc
+++ b/runtime/signal_catcher.cc
@@ -25,6 +25,8 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <sstream>
+
 #include "base/unix_file/fd_file.h"
 #include "class_linker.h"
 #include "gc/heap.h"