Fix found by PVS-Studio issues (#490)

Small changes, essentially cleanup, with no actual code logic change. 
* Ensure symbol_buffer aligned same as SYMBOL_INFO
* Use constexpr for compile-time constant
* Use = default for ctor bodies to allow compiler optimize them
* Pass string by reference to prevent copying, other smaller types we can  avoid passing by reference as the type is cheaper to copy.

src/filesink.cpp

@@ -92,7 +92,7 @@ namespace g3 {
       ss_change.str("");
 
       std::string old_log = _log_file_with_path;
-      _log_file_with_path = prospect_log;
+      _log_file_with_path = std::move(prospect_log);
       _outptr = std::move(log_stream);
       ss_change << "\n\tNew log file. The previous log file was at: ";
       ss_change << old_log << "\n";

src/filesinkhelper.ipp

@@ -51,7 +51,7 @@ namespace g3 {
          return prefix;
       }
 
-      std::string pathSanityFix(std::string path, std::string file_name) {
+      std::string pathSanityFix(std::string path, const std::string &file_name) {
          // Unify the delimeters,. maybe sketchy solution but it seems to work
          // on at least win7 + ubuntu. All bets are off for older windows
          std::replace(path.begin(), path.end(), '\\', '/');
@@ -88,7 +88,7 @@ namespace g3 {
       std::string createLogFileName(const std::string &verified_prefix, const std::string &logger_id) {
          std::stringstream oss_name;
          oss_name << verified_prefix << ".";
-         if( logger_id != "" ) {
+         if( !logger_id.empty() ) {
             oss_name << logger_id << ".";
          }
          auto now = std::chrono::system_clock::now();

src/g3log/atomicbool.hpp

@@ -18,7 +18,7 @@ namespace g3 {
       std::atomic<bool> value_;
     public:
       atomicbool(): value_ {false} {}
-      atomicbool(const bool& value): value_ {value} {}
+      atomicbool(bool value): value_ {value} {}
       atomicbool(const std::atomic<bool>& value) : value_ {value.load(std::memory_order_acquire)} {}
       atomicbool(const atomicbool& other): value_ {other.value_.load(std::memory_order_acquire)} {}
 
@@ -32,9 +32,9 @@ namespace g3 {
          return *this;
       }
 
-   bool operator==(const atomicbool& rhs)  const {
-      return (value_.load(std::memory_order_acquire) == rhs.value_.load(std::memory_order_acquire));
-   }
+      bool operator==(const atomicbool& rhs)  const {
+         return (value_.load(std::memory_order_acquire) == rhs.value_.load(std::memory_order_acquire));
+      }
 
       bool value() {return value_.load(std::memory_order_acquire);}
       std::atomic<bool>& get() {return value_;}

src/g3log/logmessage.hpp

@@ -67,8 +67,8 @@ namespace g3 {
 
       std::string threadID() const;
 
-      void setExpression(const std::string expression) {
-         _expression = expression;
+      void setExpression(std::string expression) {
+         _expression = std::move(expression);
       }
 
 
@@ -149,6 +149,7 @@ namespace g3 {
    struct FatalMessage : public LogMessage {
       FatalMessage(const LogMessage& details, g3::SignalType signal_id);
       FatalMessage(const FatalMessage&);
+      FatalMessage& operator=(const FatalMessage&) = delete;
       virtual ~FatalMessage() {}
 
       LogMessage copyToLogMessage() const;

src/g3log/shared_queue.hpp

@@ -34,7 +34,7 @@ class shared_queue
    shared_queue(const shared_queue &other) = delete;
 
 public:
-   shared_queue() {}
+   shared_queue() = default;
 
    void push(T item) {
       {

src/g3log/sinkhandle.hpp

@@ -30,7 +30,7 @@ namespace g3 {
       SinkHandle(std::shared_ptr<internal::Sink<T>> sink)
          : _sink(sink) {}
 
-      ~SinkHandle() {}
+      ~SinkHandle() = default;
 
 
       // Asynchronous call to the real sink. If the real sink is already deleted

src/g3log/time.hpp

@@ -49,7 +49,7 @@ namespace g3 {
    /** return time representing POD struct (ref ctime + wchar) that is normally
    * retrieved with std::localtime. g3::localtime is threadsafe which std::localtime is not.
    * g3::localtime is probably used together with @ref g3::systemtime_now */
-   tm localtime(const std::time_t& time);
+   tm localtime(std::time_t time);
 
    /** format string must conform to std::put_time's demands.
    * WARNING: At time of writing there is only so-so compiler support for

src/logmessage.cpp

@@ -164,7 +164,7 @@ namespace g3 {
 #endif
       , _file_path(file)
       , _line(line)
-      , _function(function)
+      , _function(std::move(function))
       , _level(level) {
    }
 

src/stacktrace_windows.cpp

@@ -120,7 +120,7 @@ namespace {
 
       DWORD64 displacement64;
       DWORD displacement;
-      char symbol_buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME];
+      alignas(SYMBOL_INFO) char symbol_buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME];
       SYMBOL_INFO *symbol = reinterpret_cast<SYMBOL_INFO *>(symbol_buffer);
       symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
       symbol->MaxNameLen = MAX_SYM_NAME;
@@ -216,7 +216,7 @@ namespace stacktrace {
          }); // Raii sym cleanup
 
 
-         const size_t kmax_frame_dump_size = 64;
+         constexpr size_t kmax_frame_dump_size = 64;
          std::vector<uint64_t>  frame_pointers(kmax_frame_dump_size);
          // C++11: size set and values are zeroed
 

src/time.cpp

@@ -129,7 +129,7 @@ namespace g3 {
 
 
 
-   tm localtime(const std::time_t& ts) {
+   tm localtime(std::time_t ts) {
       struct tm tm_snapshot;
 #if (defined(WIN32) || defined(_WIN32) || defined(__WIN32__))
       localtime_s(&tm_snapshot, &ts); // windsows