[gtk-doc] Support silent build rules with automake 1.11

[Javier Jardón <jjardon src gnome org>]

commit 311aaabddfcae13df2b169df89e140a1b9b56cb7
Author: Javier Jardón <jjardon gnome org>
Date:   Thu Dec 17 21:05:58 2009 +0100

    Support silent build rules with automake 1.11
    
    Support silent build rules, requires at least automake-1.11.
    Disable by either passing --disable-silent-rules to configure or
    passing V=1 to make.

 configure.ac |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f07a4cf..724884c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,6 +13,11 @@ AC_CONFIG_SRCDIR([gtkdoc-common.pl.in])
 AM_INIT_AUTOMAKE([check-news std-options])
 AM_MAINTAINER_MODE
 
+# Support silent build rules, requires at least automake-1.11. Disable
+# by either passing --disable-silent-rules to configure or passing V=1
+# to make
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
+
 dnl Forcing a non-null ACTION-IF-NOT-FOUND disables scrollkeeper if
 dnl gnome-doc-utils is not found but does not invalidate the build.
 GNOME_DOC_INIT([],[],enable_scrollkeeper=no)