Removed Inbox from core (unused since 4b2a66ed29)

Added the following FIXME:
How should a Twitter user get their Inbox filled with foreign tweets?

Every imported Twitter user has a profile in the Profile table, so we
could setup a Subscription entry for each of those, meaning they get
collected in the InboxNoticeStream... But this would mean a lot of
unnecessary entries and listings that generally just point to the
locked down Twitter service.

Let's figure out a good relation so we can connect any profile to any
imported foreign notice, so it shows up in the "all" feed.

plugins/TwitterBridge/scripts/streamtest.php

@@ -170,11 +170,7 @@ $stream->hookEvent('status', function($data, $context) {
         $importer = new TwitterImport();
         printf("\timporting...");
         $notice = $importer->importStatus($data);
-        if ($notice instanceof Notice) {
-            global $myuser;
-            Inbox::insertNotice($notice, $myuser->id);
-            printf(" %s\n", $notice->id);
-        } else {
+        if (!$notice instanceof Notice) {
             printf(" FAIL\n");
         }
     }