RAToast.xcodeproj: Updated the XCode settings for build architecture.
RAToastAnimationDelegate.h: Added the animation completion handler definition.
Implementation and clean up of the animation and user interaction code.

- Fixed the `swipe` user interaction.
- Implemented the `tap` user interaction.
- Added flags for enabling/disabling both type of user interactions.
- Refactored the animation code.
- More documentation.