Add getter for AttrClass and fix from_string function

Gir.toml

@@ -18,7 +18,6 @@ generate = [
     "Pango.CoverageLevel",
     "Pango.Direction",
     "Pango.EllipsizeMode",
-    "Pango.FontDescription",
     "Pango.FontFace",
     "Pango.FontFamily",
     "Pango.FontMap",
@@ -65,6 +64,14 @@ status = "generate"
     #out param
     ignore = true
 
+[[object]]
+name = "Pango.FontDescription"
+status = "generate"
+    [[object.function]]
+    name = "from_string"
+        [object.function.return]
+        nullable = false
+
 [[object]]
 name = "Pango.Font"
 status = "generate"

src/attribute.rs

@@ -0,0 +1,16 @@
+// Copyright 2017, The Gtk-rs Project Developers.
+// See the COPYRIGHT file at the top-level directory of this distribution.
+// Licensed under the MIT license, see the LICENSE file or <http://opensource.org/licenses/MIT>
+
+use Attribute;
+use AttrClass;
+use glib::translate::from_glib_full;
+use glib::translate::ToGlibPtr;
+
+impl Attribute {
+    pub fn get_attr_class(&self) -> AttrClass {
+        unsafe {
+            from_glib_full((*self.to_glib_none().0).klass)
+        }
+    }
+}

src/auto/font_description.rs

@@ -193,7 +193,7 @@ impl FontDescription {
         }
     }
 
-    pub fn from_string(str: &str) -> Option<FontDescription> {
+    pub fn from_string(str: &str) -> FontDescription {
         unsafe {
             from_glib_full(ffi::pango_font_description_from_string(str.to_glib_none().0))
         }

src/lib.rs

@@ -19,6 +19,7 @@ pub mod prelude;
 
 pub mod attr_class;
 pub use attr_class::AttrClass;
+pub mod attribute;
 pub mod font_description;
 pub mod item;
 pub use item::Item;