get rid of piForeach

apply some code analyzer recommendations
ICU flag now check if libicu exists
prepare for more accurate growth of containers (limited PoT, then constantly increase size)

libs/main/thread/pithreadpoolloop.h

@@ -83,7 +83,7 @@ public:
 private:
 	PIVector<PIThread *> threads;
 	std::function<void(int)> func;
-	std::atomic_int counter;
+	std::atomic_int counter = {0};
 };