Remove non-const PcaModel getter of MorphableModel

It's no longer necessary, since the RNG is no longer part of PcaModel.

include/eos/morphablemodel/MorphableModel.hpp

@@ -82,20 +82,6 @@ public:
 		return shape_model;
 	};
 
-	/**
-	 * Returns the PCA shape model of this Morphable Model.
-	 *
-	 * We need to have a non-const version because PcaModel::draw_sample(float)
-	 * is non-const and modifies the object (the RNG). Maybe the RNG-stuff should
-	 * be moved out of PcaModel into a free function that generates random coefficients.
-	 *
-	 * @return The shape model.
-	 */
-	PcaModel& get_shape_model()
-	{
-		return shape_model;
-	};
-
 	/**
 	 * Returns the PCA colour (albedo) model of this Morphable Model.
 	 *
@@ -106,20 +92,6 @@ public:
 		return color_model;
 	};
 
-	/**
-	 * Returns the PCA colour (albedo) model of this Morphable Model.
-	 *
-	 * We need to have a non-const version because PcaModel::draw_sample(float)
-	 * is non-const and modifies the object (the RNG). Maybe the RNG-stuff should
-	 * be moved out of PcaModel into a free function that generates random coefficients.
-	 *
-	 * @return The colour model.
-	 */
-	PcaModel& get_color_model()
-	{
-		return color_model;
-	};
-
 	/**
 	 * Returns the mean of the shape- and colour model as a Mesh.
 	 *