Converted FahrplanFavoritesManager to QAbstractListModel.

See discussion in issues #52 & #62 at https://github.com/smurfy/fahrplan.
Updated UI to use the new list model for favorites.

See #62 and discussion in #52.
Merge branch 'master' into listmodels

Conflicts:
	src/fahrplan.h
Added QAbstractListModel for storing stations list.

Search results and favorites will derive from it.

Also added Station struct which represents a station. See #62 for details.
Changed FahrplanFavoritesManager and added StationSearchResults clas:

- renamed FahrplanFavoritesManager into Favorites;
- removed duplicate code from Favorites and made it child of
  StationsListModel;
- added StationSearchResults class that will represent search for station
  results;
- removed mainwindow.cpp from being built on BlackBerry 10.

WARNING: Broken state!
Integrated StationSearchResults into Fahrplan.

WARNING: UI is in the broken state.
[N9,SYM,BB10] Added BusyLabel component.
[N9,SYM,BB10] Have only one instance of FahrplanBackend component.

Defined in MainPage.qml and visible in other pages as a "global" variable.

Same with InfoBanner, but it's defined in main.qml.
[N9,SYM,BB10] Adapted UI to use the new list model approach.
Pass Station instead of QString when searching for journey and timetable.

See #24 for details.
[HAFAS XML] Use station ID when searching for journey and timetable.

See #24 for details.
[HAFAS Binary] Use station ID when searching for journey.

See #24 for details.

As a side effect, fixes #30 - bahn.de backend is not working for (at least
one) particular station.
Save selected stations and favorites per backend.

Now that we use backend-specific IDs for querying, it doesn't make sense
to save selected stations and favorites independenly from the backend. So
these values are saved per backend.
Clear search results when starting new search for station.
Merged QDate date and QTime time parameters into one QDateTime dateTime.
Added mode and dateTime properties to Fahrplan class.
[N9,SYM,BB10] Use mode and dateTime properties of FahrplanBackend in UI.
Added few more error code descriptions to HAFAS Binary backend.

Changed parameter from int to StationType in Fahrplan::swapStations() and
Fahrplan::resetStation() methods.
[N9,SYM,BB10] Remember last active tab in StationSelect during app run.
[XML VastTrafic] Use station ID when searching for journey or timetable.

See #24 for details.