Remove the partners of VP outliers

Adds the possibility (enabled by default) to remove the partner outliers for the VP outliers. The VP now has one hit represented twice, as x and y hit. If one of the hits (either x or y) is found to be the outlier, the corresponding partner outlier (if original outlier x, then partner us y and vice verse) is found and also deactivated. This procedure can be switched on/off with the m_removeVPOutlierPartner boolean flag. This will be useful for comparison with 2D Measurements approach.