LU-120 the perfect storm

LU-120 the perfect storm

There is a corner case in the debian patching/unpatching process
where a patch converts the use of a given file to a file.in that is
to be substed.  The problem is that between the configure and the
make debs, a file, which a debian patch wants to remove already
exists (it was created by the configure) and dpkg-buildpackage's
unpatch step fails becuase it wants to try to create a file which
configure already created.

Signed-off-by: Brian J. Murrell <brian@whamcloud.com>
Change-Id: I185e496b82687d21ea3d744e939536c106b702f9
Reviewed-on: http://review.whamcloud.com/308
Tested-by: Hudson
Reviewed-by: Robert Read <rread@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>