move isatty() check into InitOutput()
Use a APT::VersionSet instead of a VersionList

Use a APT::VersionSet instead of a APT::VersionList in DoDownload()
to ensure that there is only one version in the set even if the
user passes multiple identical name/versions on the commandline
(Bug#738103)
Merge remote-tracking branch 'mvo/debian/sid' into debian/sid

Conflicts:
	test/integration/test-apt-get-download
l10n: vi.po (621t): Update and review

Signed-off-by: Trần Ngọc Quân <vnwildman@gmail.com>
remove duplicated apt-get download apt apt test
releasing package apt version 0.9.15.2
use "Restrictions: allow-stderr and avoid apt-stderr.log in debian/tests/run-tests
trivial indent fix
do not recommend dselect in apt-get manpage

The current description says:
"Many users find dselect intimidating and new users may prefer to use
 apt-based user interfaces."
It doesn't feel right to refer users to it then.

Closes: 617625
report https download start only if we really get it

Reporting it via progress means that e.g. a redirect will trigger it,
too, so you get a Get & Hit while http only reports a Hit as it should
be.
allow http protocol to switch to https

switch protocols at random is a bad idea if e.g. http can switch to
file, so we limit the possibilities to http to http and http to https.

As very few people (less than 1% according to popcon) have https
installed this likely changes nothing in terms of failure. The commit is
adding a friendly hint which package needs to be installed though.
enforce 'house-style' on changelog testcase

Git-Dch: Ignore
do not compress .xhtml files and remove junk files

dh_compress compresses .xhtml files by default, which breaks our doxygen
documentation. doxygen has also a bunch of temporary files it creates
which stay in the build directory and so we remove them before
installing them as documentation.

Closes: 738933