Reworked and reorganized a few of the drawables to match the current
scheme of the app. Drawables used in drawer are drawer_<name>, menu
items are ic_menu_<name>, buttons are btn_<name>_<value>.
Small redesign to spark logo.
Added gps location marker to content (only shows if content has a
location). Clicking on the location hides the list and moves to that
content on the map.