cpp: Do not use namespace using-directives

Use using-declarations instead.  [build/namespaces]

src/endgame.cpp

@@ -17,6 +17,8 @@
 #include <string>
 #include "endgame.h"
 
+using std::string;
+
 #ifdef ENDGAME_LEARNING
 static constexpr int endgameHashSize = 0x1000000; // 16M
 HashMap<Key, Endgame> endgameHashMap(endgameHashSize);

src/endgame.h

@@ -21,13 +21,10 @@
 
 #ifdef ENDGAME_LEARNING
 
-#include <vector>
-
 #include "hashmap.h"
 #include "types.h"
 
-using namespace std;
-using namespace CTSL;
+using CTSL::HashMap;
 
 static const int SAVE_ENDGAME_EVERY_N_GAMES = 256;
 

src/misc.cpp

@@ -57,7 +57,17 @@ typedef bool (*fun3_t)(HANDLE, CONST GROUP_AFFINITY*, PGROUP_AFFINITY);
 #include "misc.h"
 #include "thread.h"
 
-using namespace std;
+using std::cerr;
+using std::cin;
+using std::cout;
+using std::endl;
+using std::ifstream;
+using std::iostream;
+using std::ofstream;
+using std::setfill;
+using std::setw;
+using std::streambuf;
+using std::stringstream;
 
 namespace {
 
@@ -524,7 +534,7 @@ void bindThisThread(size_t)
 
 /// best_group() retrieves logical processor information using Windows specific
 /// API and returns the best group id for the thread with index idx. Original
-/// code from Texel by Peter Österlund.
+/// code from Texel by Peter A-terlund.
 
 int best_group(size_t idx)
 {

src/search.h

@@ -25,7 +25,7 @@
 #include "stopwatch.h"
 #endif
 
-using namespace std;
+using std::vector;
 
 namespace Search {
 

src/thread.cpp

@@ -30,18 +30,22 @@
 #include "engine_main.h"
 #endif
 
-ThreadPool Threads; // Global object
-
 #ifdef OPENING_BOOK
 #include <deque>
-using namespace std;
 #endif
 
+using std::cout;
+using std::endl;
+using std::fixed;
+using std::setprecision;
+
 #if _MSC_VER >= 1600
 #pragma warning(disable : 4695)
 #pragma execution_character_set("ANSI")
 #endif
 
+ThreadPool Threads; // Global object
+
 /// Thread constructor launches the thread and waits until it goes to sleep
 /// in idle_loop(). Note that 'searching' and 'exit' should be already set.
 

src/thread.h

@@ -34,6 +34,8 @@
 #include <QObject>
 #endif // QT_GUI_LIB
 
+using std::string;
+
 /// Thread class keeps together all the thread-related stuff. We use
 /// per-thread pawn and material hash tables so that once we get a
 /// pointer to an entry its life time is unlimited and we don't have

src/tt.h

@@ -20,7 +20,7 @@
 #include "hashmap.h"
 #include "types.h"
 
-using namespace CTSL;
+using CTSL::HashMap;
 
 #ifdef TRANSPOSITION_TABLE_ENABLE