Added a base class SettingsPreferenceFragment from which the settings activities should
be derived so that they can behave like fragments. It contains some commonly called
utility methods and dialog conversion to DialogFragment.
Some of the top-level activities can be launched directly without the left pane.
Settings.java acts as a proxy activity that contains just that settings fragment without
the left pane.
There are still a lot of second and third level activities that need to be fragmentized.
This is just the first pass to test the 2-pane layout.
Remove the two formats that have a spelled-out month, since applications
using this setting are trying to format numeric dates.
Do not forcibly set the setting the first time you go into Date & Time --
let the setting remain null if it was null before.
Add a choice corresponding to null to the list of format options. It will
look like "Normal (12-31-2009)" in the list, and will cause the system
to use whatever numeric format the locale calls for.
For the other choices, feed them to the locale-aware formatter so they
will appear with the punctuation that the locale calls for.
