Tweak onClick() code to behave like AlertDialog is expected to

Couple things:
- List clicks and button clicks don't interfere with each other
- Multichoice clicks shouldn't autodismiss

This is more realistic behavior for an alert dialog with many listener interfaces. This should also not interfere with existing implementations (and fix it for anyone that needs the listeners to behave separately)
Update sample and README with more complex listener examples
Merge pull request #124 from hzsweers/master

Tweak onClick() code to behave like AlertDialog is expected to