Clean up remnants of old progress-bar support from
AddressActionProvider.

Restore URL in address bar on close from internal cancel button (but not
yet from an external cancellation).
When filtering, add a button to the info bar to clear all filters.

Closes #9
Start using fragments for activity components.  First, the text filter
component.
Move infobar into its own fragment as well.
Cleaned up code after pulling out the text filter and infobar activity
fragments, and documented the fragments.
Moved seek bar into the main layout, in preparation for separating it
into a fragment.
Start roughing in the fragment for the main display area.
Switch to the layout fragment for MainDisplayFragment, but the
controller logic is still mainly in MainActivity.
Finished splitting out the MainDisplayFragment, though MainActivity
could use a lot of refactoring now.
Fix an issue with the seek bar in the MainDisplayFragment.
Fix menus for subactivities.

Add help to every menu, with icon.

Move some common code into ActivitiesUtil.

Close soft keyboard when finished editing a bookmark.

Put the bookmark save in the action bar itself.
Add missing files from last commit.
Remove unused declarations from MainActivity.
Move AddressActionProvider.

Close the soft keyboard when the address bar closes with the cancel
button.
Pass all lint warning: remove unused icons and string resources, and
make sure all other resources are translated.

Clean up and simplify AddressActionProvider.
Revert to non-selectable text until I figure out how to handle clicking
on links.
Handle intents for CSV files (including local ones).
Remove old search metadata.
Using intents now, instead of opening links directly.

Can open local files.

Can handle CSV from the browser.
Text is selectable.

Use Android's built-in implicit linking.