fix new warnings and escape apply namespace

- `std::apply` is part of C++17 and the compiler wants to use it because
of ADL. Thus it is now necessary to escape it as `::apply`.
- remove some `using namespace std` remaining in the sources.
- fix simple warnings.

moeo/tutorial/examples/flowshop/FlowShopBenchmarkParser.cpp

@@ -45,25 +45,25 @@ FlowShopBenchmarkParser::FlowShopBenchmarkParser(const std::string _benchmarkFil
 }
 
 
-const unsigned int FlowShopBenchmarkParser::getM()
+unsigned int FlowShopBenchmarkParser::getM()
 {
     return M;
 }
 
 
-const unsigned int FlowShopBenchmarkParser::getN()
+unsigned int FlowShopBenchmarkParser::getN()
 {
     return N;
 }
 
 
-const std::vector< std::vector<unsigned int> > FlowShopBenchmarkParser::getP()
+std::vector< std::vector<unsigned int> > FlowShopBenchmarkParser::getP()
 {
     return p;
 }
 
 
-const std::vector<unsigned int> FlowShopBenchmarkParser::getD()
+std::vector<unsigned int> FlowShopBenchmarkParser::getD()
 {
     return d;
 }

moeo/tutorial/examples/flowshop/FlowShopBenchmarkParser.h

@@ -60,25 +60,25 @@ class FlowShopBenchmarkParser
     /**
      * the number of machines
      */
-    const unsigned int getM();
+    unsigned int getM();
 
 
     /**
      * the number of jobs
      */
-    const unsigned int getN();
+    unsigned int getN();
 
 
     /**
      * the processing times
      */
-    const std::vector < std::vector < unsigned int > > getP();
+    std::vector < std::vector < unsigned int > > getP();
 
 
     /**
      * the due-dates
      */
-    const std::vector < unsigned int > getD();
+    std::vector < unsigned int > getD();
 
 
     /**

moeo/tutorial/examples/flowshop/FlowShopObjectiveVectorTraits.cpp

@@ -38,13 +38,13 @@
 #include <FlowShopObjectiveVectorTraits.h>
 
 
-bool FlowShopObjectiveVectorTraits::minimizing (int _i)
+bool FlowShopObjectiveVectorTraits::minimizing (int /*_i*/)
 {
   // minimizing both
   return true;
 }
 
-bool FlowShopObjectiveVectorTraits::maximizing (int _i)
+bool FlowShopObjectiveVectorTraits::maximizing (int /*_i*/)
 {
   // minimizing both
   return false;