Various event fixes

 * Prevents double-loading of event list fragment in StartActivity
 * Adds fade out/in animation in StartActivity when swapping fragments
 * Fixes regex for event short names (these changes should probably be duplicated on the website)
 * Changes event lists to use the event short name. With the header of event type (regional, district, etc.), having the full name for each list item seemed redundant.

Regarding the Travis builds, I updated my gradle build tools and Android tools to the latest versions (0.11 & 19.1.0, respectively). However, it looks like Travis hasn't gotten at least the latest Android SDK Build-tools yet. That's why the build is failing.