Add version.{h,cpp}: Returning version info

Makefile

@@ -55,6 +55,8 @@ gtest: $(GTESTS_TESTDIR)/*.cpp $(GTEST_OBJECTS)
 %.o:%.cpp
 	$(CXX) ${CXXFLAGS} ${LDFLAGS} ${INCLUDEFLAGS} -c -o $@ $<
 
+version.o:version.cpp
+	$(CXX) ${CXXFLAGS} ${LDFLAGS} ${INCLUDEFLAGS} -DGITCOMMIT=\"$(shell git rev-parse --short HEAD)\" -c -o $@ $<
 clean:
 	rm -f $(OBJECTS) $(DEPENDS)