Refactored how/when python interpretor is created to simplify library usage

tools/ReduceGraph/main.cpp

@@ -37,9 +37,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <rtabmap/utilite/UTimer.h>
 #include <rtabmap/utilite/UFile.h>
 #include <rtabmap/utilite/UStl.h>
-#ifdef RTABMAP_PYTHON
-#include <rtabmap/core/PythonInterface.h>
-#endif
 #include <pcl/filters/filter.h>
 #include <pcl/io/ply_io.h>
 #include <pcl/io/obj_io.h>
@@ -119,10 +116,6 @@ int main(int argc, char * argv[])
 	printf("  keep_linked = %s\n", keepLinked?"true":"false");
 	printf("  pre_cleanup = %s\n", preCleanup?"true":"false");
 
-#ifdef RTABMAP_PYTHON
-	rtabmap::PythonInterface pythonInterface;
-#endif
-	
 	// Just parse logging options
 	Parameters::parseArguments(argc, argv);