build: Fix autogen.sh with srcdir != builddir
diff --git a/autogen.sh b/autogen.sh
index 3292973..f45d20f 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,4 +1,11 @@
 #!/bin/sh
+
+olddir=`pwd`
+srcdir=`dirname $0`
+test -z "$srcdir" && srcdir=.
+
+cd "$srcdir"
+
 gprefix=`which glibtoolize 2>&1 >/dev/null`
 if [ $? -eq 0 ]; then 
   glibtoolize --force
@@ -10,6 +17,8 @@
 automake --add-missing
 autoconf
 
+cd "$olddir"
+
 if [ -z "$NOCONFIGURE" ]; then
-    ./configure "$@"
+    $srcdir/configure "$@"
 fi