Some bugs fixed.

Use `LegacyBar` instead of `ActionBar` in `FragmentTabActivity`.https://github.com/aaronmix/MonoDroid.ActionBar/commit/1a6e1680674cf77e68133fec0b2eee54d068fe24

Add the missing `MenuId` in `HomeActivity`. https://github.com/aaronmix/MonoDroid.ActionBar/commit/a3005ff3497e6f5d37c5954a56f9636eaac9ff6f This will cause exception when the user clicks the physical menu button. My device is Motoroal Droid. It runs Android 4.0 but still has physical menu button.