Merge remote-tracking branch 'origin/topic/seth/json-formatter'

* origin/topic/seth/json-formatter:
  Updating a couple of tests.
  Expanded support for modifying the timestamp format in the JSON formatter.
  Ascii input reader now supports all config options per-input stream.
  Added an option to the JSON formatter to use ISO 8601 for timestamps.
  Refactored formatters and updated the the writers a bit.

Includes some minor bugfixes and cleanup at various places, including
in old code.

src/logging/writers/Ascii.h

@@ -6,7 +6,8 @@
 #define LOGGING_WRITER_ASCII_H
 
 #include "../WriterBackend.h"
-#include "threading/AsciiFormatter.h"
+#include "threading/formatters/Ascii.h"
+#include "threading/formatters/JSON.h"
 
 namespace logging { namespace writer {
 
@@ -53,7 +54,10 @@ private:
 	string unset_field;
 	string meta_prefix;
 
-	AsciiFormatter* ascii;
+	bool use_json;
+	string json_timestamps;
+
+	threading::formatter::Formatter* formatter;
 };
 
 }