New notifications

- Added request.notifications
- Email configuration fixes
  - Set config_spec default SMTP port to `0` and switch to SSL/non-SSL
    default if `port == 0`
  - Added email_smtp_use_ssl configuration setting
- Added migrations for notification tables
- Added __repr__ to MediaComment(Mixin)
- Added MediaComment.get_entry => MediaEntry
- Added CommentSubscription, CommentNotification, Notification,
  ProcessingNotification tables
- Added notifications.task to celery init
- Fixed a bug in the video transcoder where pygst would hijack the
  --help argument.
- Added notifications
  - views
    - silence
    - subscribe
  - routes
  - utility methods
  - celery task
- Added half-hearted .active comment CSS style
- Added quick JS to show header_dropdown
- Added fragment template to show notifications in header_dropdown
- Added fragment template to show subscribe/unsubscribe buttons on
  media/comment pages
- Updated celery setup tests with notifications.task
- Tried to fix test_misc tests that I broke
- Added notification tests
- Added and extended tests.tools fixtures
- Integrated new notifications into media_home, media_post_comment views
- Bumped SQLAlchemy dependency to >= 0.8.0 since we need polymorphic for
  the notifications to work

mediagoblin/static/css/base.css

@@ -384,6 +384,12 @@ a.comment_whenlink:hover {
   margin-top: 8px;
 }
 
+.comment_active {
+  box-shadow: 0px 0px 15px 15px #378566;
+  background: #378566;
+  color: #f7f7f7;
+}
+
 textarea#comment_content {
   resize: vertical;
   width: 100%;

mediagoblin/static/js/notifications.js

@@ -0,0 +1,18 @@
+'use strict';
+var notifications = {};
+
+(function (n) {
+    n._base = '/';
+    n._endpoint = 'notifications/json';
+
+    n.init = function () {
+        $('.notification-gem').on('click', function () {
+            $('.header_dropdown_down:visible').click();
+        });
+    }
+
+})(notifications)
+
+$(document).ready(function () {
+    notifications.init();
+});