fix git-annex test -p

test: When limiting tests to run with -p, work around tasty limitation by
automatically including dependent tests.

This fixes a reversion because it didn't used to use dependencies and
forced tasty to run the init tests first. That changed when parallelizing
the test suite.

It will sometimes do a little more work than strictly required,
because it adds init tests deps when limited to eg quickcheck tests,
which don't depend on them. But this only adds a few seconds work.

Sponsored-by: Dartmouth College's Datalad project

doc/bugs/tasty_test_limiting_broken_by_concurrency.mdwn

@@ -1,14 +1,19 @@
 The changes to make `git-annex test` concurrent have
 broken using eg `git-annex test -p 'concurrent get of dup key regression'`
 
-The problem is that tasty is being run with a subset of tests in each
-runner, so most of them don't know about the test they're being limited to
-perform.
-
-There either needs to be a way to disable concurrency (eg, run all tests
-in one runner with -J1), or the code detect when tasty is limited, and
-automatically disable concurrency.
-
-Also, it looks like the repo setup test is not being run, even though it's
+It looks like the repo setup test is not being run, even though it's
 supposed to be a dependency of the test it was limited to.
 --[[Joey]]
+
+> Oh, that seems to be a limitation of tasty. From its docs:
+	
+	If Test B depends on Test A, remember that either of them may be 
+	filtered out using the --pattern option. Collecting the dependency
+	info happens after filtering. Therefore, if Test A is filtered out,
+	Test B will run unconditionally, and if Test B is filtered out,
+	it simply won't run.
+
+> This works: `git-annex test -p '/concurrent get of dup key regression/ || /Init Tests/'`
+> 
+> Ok, I was able to work around this by having git-annex test add the latter
+> pattern automatically. [[done]] --[[Joey]]