cta/CTA#130 Helgrind gets spurious when using `std::mutex` in the catalogue.

With respect to the GetOptThreadSafe class,
replaced std::mutex and std::lock_guard by
threading::Mutex and threading::MutexLocker.

common/utils/GetOptThreadSafe.cpp

@@ -18,13 +18,14 @@
 
 #include "GetOptThreadSafe.hpp"
 #include "common/exception/Exception.hpp"
+#include "common/threading/MutexLocker.hpp"
 
 #include <memory>
 
 namespace cta { namespace utils {
 
 GetOpThreadSafe::Reply GetOpThreadSafe::getOpt(const Request& request) {
-  std::lock_guard<std::mutex> lock(gMutex);
+  threading::MutexLocker locker(gMutex);
   // Prepare the classic styled argv.
   std::unique_ptr<char * []>argv(new char *[request.argv.size()]);
   char ** p=argv.get();
@@ -71,6 +72,6 @@ GetOpThreadSafe::Reply GetOpThreadSafe::getOpt(const Request& request) {
   return ret;
 }
 
-std::mutex GetOpThreadSafe::gMutex;
+threading::Mutex GetOpThreadSafe::gMutex;
 
-}} // namespace cta::utils
\ No newline at end of file
+}} // namespace cta::utils

common/utils/GetOptThreadSafe.hpp

@@ -16,11 +16,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "common/threading/Mutex.hpp"
+
 #include <vector>
 #include <string>
 #include <unistd.h>
 #include <getopt.h>
-#include <mutex>
 
 namespace cta { namespace utils {
 
@@ -45,7 +46,7 @@ public:
   };
   static Reply getOpt (const Request & request);
 private:
-  static std::mutex gMutex;
+  static threading::Mutex gMutex;
 };
 
-}} // namespace cta::utils
\ No newline at end of file
+}} // namespace cta::utils