[gupnp] Fix autogen.sh to allow non-sourcedir build

[Jens Georg <jensgeorg src gnome org>]

commit b20bc8cb9962aa84bfa156d667b03abb8827b1ac
Author: Theppitak Karoonboonyanan <thep linux thai net>
Date:   Wed Aug 22 16:03:46 2012 +0700

    Fix autogen.sh to allow non-sourcedir build
    
    * Detect $srcdir from command line
    * Create m4 subdir under $srcdir, not $builddir
    * Source gnome-autogen.sh in the same shell so that $srcdir is applied
    
    https://bugzilla.gnome.org/show_bug.cgi?id=682580

 autogen.sh |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index b02481b..60bbda0 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -20,16 +20,19 @@
 # along with this program; if not, write to the Free Software Foundation,
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
+test -n "$srcdir" || srcdir=`dirname "$0"`
+test -n "$srcdir" || srcdir=.
+
 which gnome-autogen.sh || {
     echo "You need to install gnome-common from the GNOME git"
     exit 1
 }
 
-mkdir -p m4
+test -d $srcdir/m4 || mkdir -p $srcdir/m4
 
 # require automak 1.11 for vala support
 REQUIRED_AUTOMAKE_VERSION=1.11 \
 REQUIRED_AUTOCONF_VERSION=2.64 \
 REQUIRED_LIBTOOL_VERSION=2.2.6 \
 REQUIRED_INTLTOOL_VERSION=0.40.0 \
-gnome-autogen.sh "$@"
+. gnome-autogen.sh "$@"