Modernize the code base to C++11 standards and beyond.

Apply `clang-modernize` (based on Clang 3.6) transformations to the
codebase while making sure to support Clang>=3.4 and GCC>=4.8.

We apply the transformations in parallel to speed up the quite
time consuming process, and use our `clang-format` style file
to automatically format the code respecting our coding conventions.

We use the following self-explanatory transformations:

* AddOverride
* LoopConvert
* PassByValue
* ReplaceAutoPtr
* UseAuto
* UseNullptr

This required a `compile_commands.json` compilation database, e.g.

    ccmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_EXPORT_COMPILE_COMMANDS=1

for CMake or check Bear for a Makefile based solution (or even Ninja).

    git ls-files -x '*.cpp|*.h' | \
      xargs -I{} -P $(nproc) clang-modernize -p build -final-syntax-check -format -style=file -summary -for-compilers=clang-3.4,gcc-4.8 -include . -exclude third_party {}

Boom!

References:

* http://clang.llvm.org/extra/clang-modernize.html
* http://clang.llvm.org/extra/ModernizerUsage.html

extractor/extractor.hpp

@@ -33,8 +33,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 class extractor
 {
 public:
-    extractor(const ExtractorConfig &extractor_config)
-        : config(extractor_config) {}
+  extractor(ExtractorConfig extractor_config) : config(std::move(extractor_config)) {}
     int run();
 private:
    ExtractorConfig config;

extractor/internal_extractor_edge.hpp

@@ -35,6 +35,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <boost/assert.hpp>
 
 #include <osrm/coordinate.hpp>
+#include <utility>
 
 struct InternalExtractorEdge
 {
@@ -68,18 +69,26 @@ struct InternalExtractorEdge
     }
 
     explicit InternalExtractorEdge(NodeID source,
-                           NodeID target,
-                           NodeID name_id,
-                           const WeightData& weight_data,
-                           bool forward,
-                           bool backward,
-                           bool roundabout,
-                           bool access_restricted,
-                           TravelMode travel_mode,
-                           bool is_split)
-        : result(source, target, name_id, 0, forward, backward, roundabout,
-                 access_restricted, travel_mode, is_split),
-          weight_data(weight_data)
+                                   NodeID target,
+                                   NodeID name_id,
+                                   WeightData weight_data,
+                                   bool forward,
+                                   bool backward,
+                                   bool roundabout,
+                                   bool access_restricted,
+                                   TravelMode travel_mode,
+                                   bool is_split)
+        : result(source,
+                 target,
+                 name_id,
+                 0,
+                 forward,
+                 backward,
+                 roundabout,
+                 access_restricted,
+                 travel_mode,
+                 is_split),
+          weight_data(std::move(weight_data))
     {
     }