Fix krazy issues: Use explicit constructors

* Fix all warnings about non-explicit constructors except for those
   in 3rdparty code.

src/plugins/debugger/gdb/abstractgdbadapter.h

@@ -58,7 +58,7 @@ public:
         DumperLoadedByGdb
     };
 
-    AbstractGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit AbstractGdbAdapter(GdbEngine *engine, QObject *parent = 0);
     virtual ~AbstractGdbAdapter();
 
     virtual void write(const QByteArray &data);