Added the SettingsViewController and the map type option

I tried to minimize the amount of changes to the story board to just what I
needed to get the code working; hopefully it doesn't screw anything else up.

I added the SettingsViewController class and set it up so that the map type
could be selected for the main map.
Fixed up the ConfigModel initialization from the stored state.

Removed the instantiation of the ConfigModel singleton from AppDelegate, which
was also where it was being loaded from the UserDefaults, because I suspect
that AppDelegate.m is running in a different thread than the UIViewControllers,
which is where I actually need them.  Now the ConfigModel singleton
automatically loads itself from UserDefaults if it is creating the singleton in
getConfigModel.  Now everywhere that needs it will get the one available in the
current thread, initialized properly, and any time that changes are made, the
changes should be saved right then.
Factored out the map object creation

Since I want to re-draw the map objects when we come back to the
MapViewController, I factored out the code that queries the database and
creates the map objects for overlay on the map.  Now that code is called again
every time that the viewWillAppear method is called by the system.  This means
that if changes are made to the filter, the redrawing will happen
automatically.
Added the auto-center on GPS setting

Added the UISwitch on the Settings scene to toggle whether the map will
auto-center on the GPS.

Also changed the method that SettingsViewController overrides to detect when
the view is being switched away from, which is when the ConfigModel is
committed to the UserDefaults.
Added vim modeline
Merge pull request #17 from agricocb/master

Added the SettingsViewController object and a few settings on the story board