Tests that the DAO indexes posts in the background

And:
- Add some type aliases, e.g. PostId
- Pass an Akka actor system to the DAO factory
Remove pointless database version = 0.0.2 test.
Entitle login submit button "Login and Post", if posting a comment

I got some user feedback that "Login" only was confusing.
Change dialog background to white

Use a new jQuery UI CSS version (but keep old JS scripts for now).
Rename packages

Rename com.debiki.v0 => {core, dao.rdb, tck.dao}. Also reorder some import
statements alphabetically.
Rename test helper to CancelAllOnFirstFailure.
Delete debiki-tck-dao build file

Build config is specified in parent project debiki-server actually.
Rename things that were renamed in debiki-dao-rdb.
Rename project debiki-dao-pgsql to -rdb (but not submodule directory).
Rename things from "...tenant..." to "...site...".
Move Api/Page/SafeActions to separate `actions` package.
Move [Debiki/Api/Page]Request to separate package.
Print which E2E test is being run.
Fix broken E2E test: admin should see unapproved comments.
E2E tests: Fix delete comments test bug.
E2E tests: Specify exactly which "Post as ..." button to click

Otherwise it seems the test hangs on the "Post as ..." click — I suppose it
clicked some hidden submit button instead?
Fix E2E test: Wrap `click` in `eventually { ... }`.
E2E tests: Fix tests by wrapping things in `eventually { ... }`.
Show "Thread deleted by ..." message

But only directly after deleting the thread. Not after page reload.  This also
fixes a broken E2E test: DeleteActivitySpec.
Upgrade ScalaTest from 2.0.M6-SNAP8 to 2.0.RC1-SNAP4

I'm getting the impression that this makes @DoNotDiscover work?  Also with
Suites, not only Specs.