Date and time localization + calendar event text format selection

**Note:** I've had some spare time while visiting Qt Developer Days this year, but I didn't have my N9 with me, so Harmattan changes were made "blindly". You should check whether they work before merging these changes. To check AM/PM alignment just add `QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));` right after `QApplication` creation in `main.cpp`. Then search for a journey that includes departure/arrival times both earlier than 9:59 and later than 10:00.

1\. Date and time formating is now taken from the system locale. We could add an option to select between short and long date format in future.

2\. Added a way to switch between (slightly modified) old format:
```
--- Transport 1 ---
Date Time   Departure 1 / Platform
Date Time   Arrival 1 / Platform

--- Transport 2 ---
Date Time   Departure 2 / Platform
Date Time   Arrival 2 / Platform

-- 
Added by Fahrplan. Please, re-check the information before your journey.
```
and a new compact format:
```
Date Time   Departure 1 / Platform
--- Transport 1 ---
Date Time   Arrival 1 / Platform
Date Time   Departure 2 / Platform
--- Transport 2 ---
Date Time   Arrival 2 / Platform
```