Code modernization: subfolders (#6283)

* Code modernization: subfolders

Modernize various code on subfolders client, network, script, threading, unittests, util

* empty function
* default constructor/destructor
* for range-based loops
* use emplace_back instead of push_back
* C++ STL header style
* Make connection.cpp readable in a pointed place + typo

src/threading/semaphore.h

@@ -35,6 +35,8 @@ public:
 	Semaphore(int val = 0);
 	~Semaphore();
 
+	DISABLE_CLASS_COPY(Semaphore);
+
 	void post(unsigned int num = 1);
 	void wait();
 	bool wait(unsigned int time_ms);
@@ -47,6 +49,4 @@ private:
 #else
 	sem_t semaphore;
 #endif
-
-	DISABLE_CLASS_COPY(Semaphore);
 };