l10n: de.po: translate 38 new messages

Translate 38 new messages came from git.pot update in fe05e19
(l10n: git.pot: v2.1.0 round 1 (38 new, 9 removed)).

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
po/TEAMS: add new members to German translation team

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Merge git://github.com/git-l10n/git-po

* git://github.com/git-l10n/git-po:
  po/TEAMS: add new members to German translation team
  l10n: de.po: translate 38 new messages
t3904: fix cut-and-paste typo in test description
tests: make patch-mode test failure more verbose

Previously, a failing test of verify_state would simply exit
non-zero, causing the test to fail. This meant that it was
difficult to know which file had different contents, or what
the difference was. Instead, build it around test_cmp, which
generally shows a diff on failure.
stash apply -p WIP