Add compute() on MomentOfInertiaEstimation (#135)

Thanks for the PR. 

About test code.
0.3 At the time of release, we will implement it at once.

Author: vlobanov

pcl/pxi/Features/MomentOfInertiaEstimation_172.pxi

@@ -29,13 +29,17 @@ cdef class MomentOfInertiaEstimation:
     def __dealloc__(self):
         del self.me
 
+    # feature_extractor.compute ();
     # feature_extractor.getMomentOfInertia (moment_of_inertia);
     # feature_extractor.getEccentricity (eccentricity);
     # feature_extractor.getAABB (min_point_AABB, max_point_AABB);
     # feature_extractor.getOBB (min_point_OBB, max_point_OBB, position_OBB, rotational_matrix_OBB);
     # feature_extractor.getEigenValues (major_value, middle_value, minor_value);
     # feature_extractor.getEigenVectors (major_vector, middle_vector, minor_vector);
     # feature_extractor.getMassCenter (mass_center);
+    def compute (self):
+        self.me.compute()
+
     def get_MomentOfInertia (self):
         cdef vector[float] moment_of_inertia
         self.me.getMomentOfInertia(moment_of_inertia)

pcl/pxi/Features/MomentOfInertiaEstimation_180.pxi

@@ -29,13 +29,17 @@ cdef class MomentOfInertiaEstimation:
     def __dealloc__(self):
         del self.me
 
+    # feature_extractor.compute ();
     # feature_extractor.getMomentOfInertia (moment_of_inertia);
     # feature_extractor.getEccentricity (eccentricity);
     # feature_extractor.getAABB (min_point_AABB, max_point_AABB);
     # feature_extractor.getOBB (min_point_OBB, max_point_OBB, position_OBB, rotational_matrix_OBB);
     # feature_extractor.getEigenValues (major_value, middle_value, minor_value);
     # feature_extractor.getEigenVectors (major_vector, middle_vector, minor_vector);
     # feature_extractor.getMassCenter (mass_center);
+    def compute (self):
+        self.me.compute()
+
     def get_MomentOfInertia (self):
         cdef vector[float] moment_of_inertia
         self.me.getMomentOfInertia(moment_of_inertia)