fix both in-tree and out-of-tree builds

fix both in-tree and out-of-tree builds

On Thu, Dec 3, 2009 at 14:31, Daniel Elstner <daniel.kitta@googlemail.com> wrote:
> However, I'd recommend to look first in the build directory, and then in
> the source directory to match the behavior of make with VPATH builds.
> The idea is that a file in the build tree, if it exists, overrides a
> file of the same name in the source tree.