dpkg-deb, dpkg-genbuildinfo and dpkg-genchanges already have flags for
output directories in a directory other than `..`. Adding this
`--no-changes` flag prevents `dpkg-buildpackage` from writing the
.changes file to `..`.

With this option, the `-O` options from `dpkg-genchanges` and `dpkg-genbuildinfo` can take care of handling the output instead of `dpkg-buildpackage`.

This change could be done by having `dpkg-genchanges` determine where
to place the .changes file, but currently `dpkg-buildpackage` does
so. That change however seems like it potentially breaks existing
behavior. Adding a flag to `dpkg-buildpackage` to override this
behavior seems preferable since it is new behavior instead of breaking
old behavior.

---
scripts/dpkg-buildpackage.pl | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/dpkg-buildpackage.pl b/scripts/dpkg-buildpackage.pl
index aacb83118..4755b5a5a 100755
--- a/scripts/dpkg-buildpackage.pl
+++ b/scripts/dpkg-buildpackage.pl
@@ -109,6 +109,7 @@ sub usage {
-us, --unsigned-source unsigned source package.
-ui, --unsigned-buildinfo unsigned .buildinfo file.
-uc, --unsigned-changes unsigned .buildinfo and .changes file.
+ --no-changes do not create .changes file.
--no-sign do not sign any file.
--force-sign force signing the resulting files.
--admindir=<directory> change the administrative directory.
@@ -166,6 +167,7 @@ my $signreleased = 1;
my $signsource = 1;
my $signbuildinfo = 1;
my $signchanges = 1;
+my $skipchanges = 0;
my $buildtarget = 'build';
my $binarytarget = 'binary';
my $host_arch = '';
@@ -271,6 +273,8 @@ while (@ARGV) {
$signsource