Revert "SERVER-6461: Ensure that nullstream instance is constructed before main()."

Also revert "check that logging framework is initialized early to avoid segfault".

This reverts commit 3e54e4c,
and commit 6f6f992.

Author: Andy Schwerin

src/mongo/util/log.cpp

@@ -62,9 +62,6 @@ namespace mongo {
         return Logstream::get().prolog();
     }
 
-    Nullstream::Nullstream() {}
-    Nullstream::~Nullstream() {}
-
     class LoggingManager {
     public:
         LoggingManager()

src/mongo/util/log.h

@@ -134,11 +134,10 @@ namespace mongo {
 
     class Nullstream {
     public:
-        Nullstream();
-        virtual ~Nullstream();
         virtual Nullstream& operator<< (Tee* tee) {
             return *this;
         }
+        virtual ~Nullstream() {}
         virtual Nullstream& operator<<(const char *) {
             return *this;
         }