German dpkg translation update

Update to 1088t2u.
Update and review Vietnamese program translations

Signed-off-by: Trần Ngọc Quân <vnwildman@gmail.com>
Signed-off-by: Guillem Jover <guillem@debian.org>
dpkg-maintscript-helper: Document environment requirements for supports

Closes: #739634
dpkg(1): Improve wording for --verify and --verify-format

Closes: #733057
build: Switch test runner from Test::Harness to TAP::Harness

The latter is the recommended module for new code, the former being just
a compatibility wrapper around it. And it will allow to set more detailed
options for the harness that are not exposed through the Test::Harness
wrapper.

We use a make variable instead of inlining the perl code in the make
recipe due to the way make escapes backslashes inside single-quotes
in recipes, which disturbs the semantics of the perl code.
build: Add new TEST_PREFIX variable to control test case execution paths

This is required as the perl test cases are in srcdir, but C based test
cases are going to be in builddir.
build: Use the perl TAP::Harness for the C test suite

The automake TAP driver only appeared once the parallel test runner
allowed custom drivers after 1.11, which we were not requesting in
the AM_INIT_AUTOMAKE call.

But simply requesting a later version is not good enough, as Debian
stable (wheezy) is still only shipping automake 1.11. Instead just switch
to use the perl TAP::Harness infrastructure for the C test suite too.

Regression introduced in commit d9833ac0b6b66e9dfaff272f6d0a25373bfff091.
build: Enable failed test case reporting from the TAP::Harness

Set the «failures» argument for the harness, so that we can get the
failing test case entries, particularly important for the C test suite,
as perl will not report a line number for those.
Dpkg::Source::Patch: Correctly parse C-style diff filenames

We need to strip the surrounding quotes, and unescape any escape
sequence, so that we check the same files that the patch program will
be using, otherwise a malicious package could overpass those checks,
and perform directory traversal attacks on source package unpacking.

Fixes: CVE-2014-0471

Reported-by: Jakub Wilk <jwilk@debian.org>
Regenerate .pot files and merge .po files with them
Release 1.17.8
Bump version to 1.17.9