autogen: Support being called from external build dir

Building libusb from another build directory doesn't properly work right
now, as calling autogen.sh from there won't work.

An example is when using jhbuild to build it.

So always use absolute paths to call configure and bootstrap scripts

Signed-off-by: Ludovic Rousseau <ludovic.rousseau@free.fr>

autogen.sh

@@ -2,7 +2,9 @@
 
 set -e
 
-./bootstrap.sh
+srcdir="$(dirname "$0")"
+
+"$srcdir"/bootstrap.sh
 if [ -z "$NOCONFIGURE" ]; then
-    exec ./configure --enable-examples-build --enable-tests-build "$@"
+    exec "$srcdir"/configure --enable-examples-build --enable-tests-build "$@"
 fi

bootstrap.sh

@@ -2,6 +2,8 @@
 
 set -e
 
+cd "$(dirname "$0")"
+
 if [ ! -d m4 ]; then
     mkdir m4
 fi

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 11608
+#define LIBUSB_NANO 11609