[Positioning] Check code with cppcheck

- Replace occurences of `container.size() == 0` with
  `container.empty()`.
- Fix an allocation in posexcept.cc (false positive?).
- UserInterface: in constructor, handle bad_alloc exception possibly
  thrown by `new`.

owlps-positioning/measurement.cc

@@ -95,7 +95,7 @@ void Measurement::clear()
 
 void Measurement::update_average_ss()
 {
-  if (ss_list.size() == 0)
+  if (ss_list.empty())
     {
       average_ss = 0 ;
       return ;
@@ -151,7 +151,7 @@ ostream &operator<<(ostream &os, const Measurement &m)
       << ": " ;
 
   // List of SS
-  if (m.ss_list.size() == 0)
+  if (m.ss_list.empty())
     os << "No values" ;
   else
     for (vector<int>::const_iterator i = m.ss_list.begin() ;

owlps-positioning/posexcept.cc

@@ -5,8 +5,10 @@
 using namespace std ;
 
 
-bad_direction::bad_direction(const char _direction) throw():
-  direction(_direction) {}
+bad_direction::bad_direction(const char _direction) throw()
+{
+  direction = _direction ;
+}
 
 
 const char* bad_direction::what() const throw()

owlps-positioning/referencepoint.cc

@@ -159,7 +159,7 @@ ostream &operator<<(ostream &os, const ReferencePoint &rp)
   os << (Point3D) rp << '\n' ;
 
   // List of requests
-  if (rp.requests.size() == 0)
+  if (rp.requests.empty())
     os << "No request." << '\n' ;
   else
     for (vector<CalibrationRequest*>::const_iterator

owlps-positioning/request.cc

@@ -112,7 +112,7 @@ ostream &operator<<(ostream &os, const Request &r)
       << ":" ;
 
   // List of Measurements
-  if (r.measurements.size() == 0)
+  if (r.measurements.empty())
     os << " No values" ;
   else
     for (unordered_map<string, Measurement>::const_iterator i

owlps-positioning/userinterface.cc

@@ -26,8 +26,16 @@ UserInterface::UserInterface(const int argc, char **argv)
   cli_argument_values = argv ;
   config_file_name = DEFAULT_CONFIG_FILE_NAME ;
 
-  cli_options = new po::options_description("General options") ;
-  file_options = new po::options_description("Parameters") ;
+  try
+    {
+      cli_options = new po::options_description("General options") ;
+      file_options = new po::options_description("Parameters") ;
+    }
+  catch (bad_alloc e)
+    {
+      throw ;
+    }
+
   fill_options() ;
 
   parse_options() ;

owlps-positioning/waypoint.cc

@@ -80,7 +80,7 @@ ostream &operator<<(ostream &os, const Waypoint &wp)
   os << (Point3D) wp ;
 
   // List of buildings
-  if (wp.buildings.size() == 0)
+  if (wp.buildings.empty())
     os << '\n' << "Belongs to no building!" ;
   else
     for (vector<Building*>::const_iterator i = wp.buildings.begin() ;