Revert "Popout inbox"

This reverts commit 31e7d285e3.

This seemed like a nice feature, but the popup bubble isn't very
conducive to nontrivial user inputs, e.g. file inputs.

Fixes #211

js/views/inbox_view.js

@@ -80,10 +80,6 @@
         events: {
             'click .fab': 'showCompose',
             'select .contact': 'openConversation',
-            'click .popout': 'popout'
-        },
-        popout: function() {
-            bg.popoutInbox();
         },
         openConversation: function(e, data) {
             bg.openConversation(data.modelId);