git-dangling: Add "exit 0" at EOF to make tests pass

After commit 6650b14 ("git-dangling: Don't delete $dangfile if it's
inside the .git dir", 2014-08-29 21:30:32 +0200) the script returned
with the exit value of the "test" statement added in that commit:

  not ok 17 - "../../../git-dangling" - Restore origin/expbranch (retval)
  #   Failed test '"../../../git-dangling" - Restore origin/expbranch (retval)'
  #   at ./git-dangling.t line 195.
  #          got: '1'
  #     expected: '0'

4fb5ebec-3755-11e4-a6a2-fefdb24f8e10
std: Output undefined tags in sorted order

Newer Perl versions have changed the order hash keys are processed or
something. Anyway, tests/std.t fails with newer Perl versions (for
example version 5.18.2 here in Linux Mint 17):

  # Check for unused tags...
  ok 23 - "SUUID_LOGDIR=tmpuuids ../../std perl-tests" - Report unused tags (stdout)
  not ok 24 - "SUUID_LOGDIR=tmpuuids ../../std perl-tests" - Report unused tags (stderr)
  #   Failed test '"SUUID_LOGDIR=tmpuuids ../../std perl-tests" - Report unused tags (stderr)'
  #   at ./std.t line 321.
  #                   'std: Warning: Undefined tags: exec filename libdir progname testcmd
  # '
  #     doesn't match '/^std: Warning: Undefined tags: testcmd filename progname exec libdir\n$/s'

To make the output identical across Perl versions, output the tags in
sorted order.

4945af70-376b-11e4-8eec-c80aa9e67bbd
std: Exit with predictable value 1 if file already exists

The old weirdness in test #28 in tests/std.t is back again, this time
with a new random exit value:

  not ok 28 - "../../std bash bashfile" - Create bash script, file
    already exists, don’t use --force (retval)
  #   Failed test '"../../std bash bashfile" - Create bash script, file
  #   already exists, don’t use --force (retval)'
  #   at ./std.t line 327.
  #          got: '255'
  #     expected: '2'

Have messed around with this exit value twice before, and it seems as
it's pretty random on different systems. So change the die() to warn()
and run exit(1) explicitly.

6d53588e-376d-11e4-af8d-c80aa9e67bbd
Merge branch 'fix-tests'

Some tests are failing with Perl v5.18.2 in Linux Mint 17, make them
pass again.

* fix-tests:
  std: Exit with predictable value 1 if file already exists
  std: Output undefined tags in sorted order
  git-dangling: Add "exit 0" at EOF to make tests pass

a9f18dec-376d-11e4-8cb6-c80aa9e67bbd