use TemplateSelector to show GroupName and BusInfo in ListBox `lbBus` of MainPage.xaml

use LongListSelector with GroupHeader to show all Buses in AddBus.xaml
use PivotItem to show stationsBack and stationsGo in AddBusStation.xaml
Add ChangeGroupName.xaml for change groupName
use Database.BusKeyName() to classify kind of bus by Regex
TODO:
 Background agent to update tile every 1 minute