Added a settings dialog where the user can change the settings with a
setting for the time notation (12-hours or 24-hours notation). GUI is
updated when the settings are saved.

Added a menu item for the settings dialog in the ActionBar and
hardware-button-menu

Implemented the time preference in the existing functionalities

Rewrote a part of the TimeHandler for easier use with the new settings
menu

Made a little change in the list_view_row.xml (referred to a string
resource instead of a hard-coded string)

Removed a superfluous comment in both the ForecastPreferencesFragment
and the RegionPreferencesFragment.