[doc] Hooks up cogl-material reference documentation

Adds some more gtk-doc comments to cogl-material.h, and adds a new section to
cogl-sections.txt

doc/reference/cogl/cogl-docs.sgml

@@ -57,6 +57,7 @@
     <xi:include href="xml/cogl-util.xml"/>
     <xi:include href="xml/cogl-matrix.xml"/>
     <xi:include href="xml/cogl-texture.xml"/>
+    <xi:include href="xml/cogl-material.xml"/>
     <xi:include href="xml/cogl-shaders.xml"/>
     <xi:include href="xml/cogl-offscreen.xml"/>
     <xi:include href="xml/cogl-fixed.xml"/>

doc/reference/cogl/cogl-sections.txt

@@ -304,3 +304,41 @@ cogl_matrix_translate
 cogl_matrix_scale
 </SECTION>
 
+<SECTION>
+<FILE>cogl-material</FILE>
+<TITLE>Materials</TITLE>
+cogl_material_new
+cogl_material_ref
+cogl_material_unref
+cogl_material_set_diffuse
+cogl_material_set_ambient
+cogl_material_set_ambient_and_diffuse
+cogl_material_set_specular
+cogl_material_set_shininess
+cogl_material_set_emission
+cogl_set_source
+CoglMaterialAlphaFunc
+cogl_material_set_alpha_test_function
+CoglMaterialBlendFactor
+cogl_material_set_blend_factors
+cogl_material_set_layer
+cogl_material_remove_layer
+CoglMaterialLayerCombineFunc
+cogl_material_set_layer_combine_function
+CoglMaterialLayerCombineChannels
+CoglMaterialLayerCombineSrc
+cogl_material_set_layer_combine_arg_src
+CoglMaterialLayerCombineOp
+cogl_material_set_layer_combine_arg_op
+cogl_material_set_layer_matrix
+cogl_material_get_cogl_enable_flags
+cogl_material_flush_gl_material_state
+cogl_material_flush_gl_alpha_func
+cogl_material_flush_gl_blend_func
+cogl_material_get_layers
+CoglMaterialLayerType
+cogl_material_layer_get_type
+cogl_material_layer_get_texture
+cogl_material_layer_flush_gl_sampler_state
+</SECTION>
+