Various improvements to mobile notifications...

Enable loading more than 20 notifications in the archive view

Set up logging capability and turn on logging for archives
and overlay view.

Disable notallunread api param for now since it doesn't do
anything yet (except throw a warning).

Add 'All notifications' link to notifications overlay.

Only load notifications overlay code for logged in users in Beta
or Alpha mode.

Also updating echo API calls per changes in Echo.

Dependency: I9fa8c4501e038ded9125c3b43e5207c355af2db9
Change-Id: I378158023cdf769cf3c4eb746f25d9f375101e4d
Merge "Various improvements to mobile notifications..."