The methods in TunnelConfig and TunnelUtil are taken almost verbatim from
IndexBean (modified to be static in TunnelUtil). The tunnel creation wizard
works now, and the new tunnel will start if auto start is enabled.

There are a lot of changes here:
- The main_content FrameLayout is now main_fragment (more logical name).
- TunnelEntry now stores a Context instead of a TunnelEntryLoader (so
  it can be instantiated inside the detail Fragment).
- The activity_navdrawer layout is now an alias to a one-pane or two-pane
  layout depending on screen size.
- Subclasses of I2PActivityBase can now override canUseTwoPanes() to enable
  and use the two-pane layout (for devices that support it).

Until changes to the list of TunnelControllers can be monitored, the Loader
refreshes the view every 10 seconds.

Router must be started and client tunnels built before loading the I2PTunnel
Activity, or it hangs when switching tabs.

Broken: cannot find net.i2p.i2ptunnel.I2PTunnel
(but it can when launching the router)