Shaders: removed deprecated texture unit enums.

Use dedicated texture setters instead.

src/Magnum/Shaders/AbstractVector.h

@@ -56,16 +56,6 @@ template<UnsignedInt dimensions> class AbstractVector: public AbstractShaderProg
          */
         typedef typename Generic<dimensions>::TextureCoordinates TextureCoordinates;
 
-        #ifdef MAGNUM_BUILD_DEPRECATED
-        enum: Int {
-            /**
-             * Vector texture binding unit
-             * @deprecated Use @ref setVectorTexture() instead.
-             */
-            VectorTextureLayer = 15
-        };
-        #endif
-
         /**
          * @brief Set vector texture
          * @return Reference to self (for method chaining)
@@ -73,12 +63,10 @@ template<UnsignedInt dimensions> class AbstractVector: public AbstractShaderProg
         AbstractVector<dimensions>& setVectorTexture(Texture2D& texture);
 
     protected:
+        enum: Int { VectorTextureLayer = 15 };
+
         explicit AbstractVector() = default;
         ~AbstractVector() = default;
-
-        #ifndef MAGNUM_BUILD_DEPRECATED
-        enum: Int { VectorTextureLayer = 15 };
-        #endif
 };
 
 /** @brief Base for two-dimensional text shaders */

src/Magnum/Shaders/Flat.h

@@ -142,17 +142,6 @@ template<UnsignedInt dimensions> class MAGNUM_SHADERS_EXPORT Flat: public Abstra
          */
         typedef typename Generic<dimensions>::TextureCoordinates TextureCoordinates;
 
-        #ifdef MAGNUM_BUILD_DEPRECATED
-        enum: Int {
-            /**
-             * Color texture binding unit. Used only if @ref Flag::Textured is
-             * set.
-             * @deprecated use @ref setTexture() instead.
-             */
-            TextureLayer = 0
-        };
-        #endif
-
         #ifdef DOXYGEN_GENERATING_OUTPUT
         /**
          * @brief Flag

src/Magnum/Shaders/Phong.h

@@ -153,31 +153,6 @@ class MAGNUM_SHADERS_EXPORT Phong: public AbstractShaderProgram {
          */
         typedef Generic3D::TextureCoordinates TextureCoordinates;
 
-        #ifdef MAGNUM_BUILD_DEPRECATED
-        enum: Int {
-            /**
-             * Ambient texture binding unit. Used only if
-             * @ref Flag::AmbientTexture is set.
-             * @deprecated Use @ref setAmbientTexture() instead.
-             */
-            AmbientTextureLayer = 0,
-
-            /**
-             * Diffuse texture binding unit. Used only if
-             * @ref Flag::DiffuseTexture is set.
-             * @deprecated Use @ref setDiffuseTexture() instead.
-             */
-            DiffuseTextureLayer = 1,
-
-            /**
-             * Specular texture binding unit. Used only if
-             * @ref Flag::SpecularTexture is set.
-             * @deprecated Use @ref setSpecularTexture() instead.
-             */
-            SpecularTextureLayer = 2
-        };
-        #endif
-
         /**
          * @brief Flag
          *