Kill mark as read button

This is being redefined as part of the introduction of notification
tabs.

Change-Id: I2211bf6727f661ca7fcd6023aaddb3f2b5ac53ba
Notification overlay Messages and Alerts sections

Shift to new API to support 2 tab view
When a new has no messages they will see the old style overlay with
Notifications heading. I have added tests to assure this is the case!

Later patches will:
1) Add the mark as read button only in message view
2) Note currently the tabs do not refresh when notifications is clear.
We need some kind of EventEmitter to make this sort of thing easier.

Change-Id: I62b590e81cd3fe867c4c13959cb43466aacfe2d5
E2b: Reflect the count in alerts and messages tabs

Add test coverage.

Change-Id: Ia5658d2b0c230915cda9309a590b416b0aa73bfe
E2c: Hover behaviour of notifications panel tabs

Note no design was defined so have taken this to mean use
mediawiki ui for consistency purposes.

* Use mw-ui-active and mw-ui-quiet for tabs
* Update tests

Change-Id: If7a51b2286cdfe6e839dacc2476c9a578bc7f1df
E2d: Add the mark as read button to messages view

Don't mark messages as read until they have been acted on.
Show a mark as read button that marks entire list as read.

Change-Id: I4450a66cffd11c67b9a4ba9aac0fe958dc760e15
F11: Show mark as read buttons in notification list items

Change-Id: I1c132a3645188c8da8b04432dd3c1ce1006cca80
Truncate text in Echo notifications

Automatically truncate text with ellipsis on single lines of title

Change-Id: I0ef9eeb9f9d3403f79ee9960b075fb7062150a1d
E2e: Show the correct value of unread messages in the tabs.

Change-Id: I976937cfe184f37abe78904e6f2cdc81f8190e80
Fix issue with tab visibility

Danny noticed a bug where if both tabs have unread notifications,
then when opening the overlay and clicking on the alerts tab, the user
would be reverted back to the messages tab.

Test stops this from happening again.

Change-Id: I6bbbbf61251957336de8856201412fa3569ab22d
Merge remote-tracking branch 'gerrit/master' into two_tabs

Change-Id: I92c94bd13bea02f43fa10aa3a05d671fe2e75116