improve error message
Fix conffile prompt regression (LP: #1260297)

This fixes a regression in the conffile prompt for the progress-fd
and adds a testcase to ensure this does not regress again.
Merge remote-tracking branch 'mvo/bugfix/conffile' into debian/sid
releasing package apt version 0.9.14.1
run autopkgtest against the installed apt
make apt-key net-update actually testable
Danish translation update
fix apt-key net-update test to use the buildin webserver
add apt-vendor for raspbian. Closes: #732749
vendor/getinfo:

* vendor/getinfo:
  - fix ubuntu-codename
vendor/steamos/*:

* vendor/steamos/*:
  - add steamos support
make /etc/apt/preferences parser deal with comment only sections
apt-pkg/contrib/gpgv.cc: use /tmp as fallback dir

if the directory given by $TMPDIR is not available, use /tmp as fallback.
factor GetTempDir out
add basic tests for GetTempDir()
add integration test
Merge branch 'feature/policy-parser-bts732746' into debian/sid
Merge branch 'feature/test-apt-key-net-update' into debian/sid
Merge branch 'feature/tests-on-installed' into debian/sid
add make -C test/interactive-helper/ to .travis.yml