[pangomm] Renderer: Add get/set_alpha().

[Murray Cumming <murrayc src gnome org>]

commit 688201f67f6f6ce77b83bee309d72e472f1dafbc
Author: Murray Cumming <murrayc murrayc com>
Date:   Sun Nov 29 20:50:34 2015 +0100

    Renderer: Add get/set_alpha().
    
    Wrapping pango_renderer_get/set_alpha(), which is new API
    in pango 1.38.

 pango/src/renderer.hg |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/pango/src/renderer.hg b/pango/src/renderer.hg
index e6b9f0e..9ac0d48 100644
--- a/pango/src/renderer.hg
+++ b/pango/src/renderer.hg
@@ -68,6 +68,9 @@ public:
 #m4 _CONVERSION(`PangoColor*',`Color',`Color($3)')
   _WRAP_METHOD(Color get_color(RenderPart part) const, pango_renderer_get_color)
 
+  _WRAP_METHOD(void set_alpha(RenderPart part, guint16 alpha), pango_renderer_set_alpha)
+  _WRAP_METHOD(guint16 get_alpha(RenderPart part) const, pango_renderer_get_alpha)
+
   _WRAP_METHOD(void set_matrix(const Matrix& matrix), pango_renderer_set_matrix)
 
   //TODO: Documentation: