The PixelFormat bit and mask #defines should not be used and are there
mostly for convenience, so we can push them to the "private" sub-section
of the API reference.
This pushed Cogl's API reference coverage to 100%.
<SUBSECTION>
CoglFuncPtr
-COGL_PIXEL_FORMAT_24
-COGL_PIXEL_FORMAT_32
-COGL_A_BIT
-COGL_BGR_BIT
-COGL_AFIRST_BIT
-COGL_PREMULT_BIT
-COGL_UNORDERED_MASK
-COGL_UNPREMULT_MASK
CoglPixelFormat
CoglBufferTarget
CoglBufferBit
cogl_shader_type_get_type
cogl_texture_flags_get_type
cogl_vertices_mode_get_type
+COGL_AFIRST_BIT
+COGL_A_BIT
+COGL_BGR_BIT
+COGL_PIXEL_FORMAT_24
+COGL_PIXEL_FORMAT_32
+COGL_PREMULT_BIT
+COGL_UNORDERED_MASK
+COGL_UNPREMULT_MASK
</SECTION>
<SECTION>