Add maildir synchronization tests for multiple messages with the same
message-id. As this is not yet implemented in notmuch, some of these
teste are marked as BROKEN.
I use $(< ) operator to avoid fiddling with stripped trailing newlines
from test results which happens when output+=$(command) is used.
This change reworks these tests in several ways:
1. Bring tests into "new" test style preferring test_expect_equal over
test_expect_success in almost all cases.
2. Don't emit test results for intermediate items not actually being
tested, (things like "no new messages", "search for message",
etc.). Those things are already covered by existing tests such as
"basic" or "search" and only serve to obscure what's actually being
tested.
3. Change sense of the test showing failure to rename a file from
"new" to "cur" when "cur" doesn't exist.
In this case, notmuch should detect that this is not a maildir and
should not attempt to do any renaming of the file.
4. Extend dump/restore test to also exercise addition of tag, not just
removal.
Both items #3 and #4 above show shortcomings in the current
implementation. These are currently resulting in test results of FAIL
and indicate bugs that need to be fixed.
