Expose conference choice better

[tecknicaltom]

Using Android Hacker Tracker at a time when multiple conferences are ongoing, it was really confusing when the active con changed in the app. Digging into the settings to change back to the con I was at was nonintuitive. I'd recommend launching the con selection popup or a new drop-down if the con name is tapped on the side pullout, or small text under the current con name to the effect of "change".