Adding some modifications on qsr class
Added the functionality to obtain a description of an scene with qualitative spatial relations between objects
Added a function to get a description with qualitative spatial relations given two objects. Code cleaned and commented
Create a function to simplify the displaying of every relations.
Code cleaned
Created a function to give all the QSR values
Added functions in the menu related with QSR. Now the program is capable to obtain descriptions using QSR, display all the values in the terminal or save it as a txt file. Also some comments has been added in the code
Fixed a bug when inserting an object. The coordinate z of the pose was the used previously with other object.
Assign a shortcut to the QSR functions
Solved the problem produced when a point cloud is not loaded correctly. Also the window title has been changed.