• Fixed issue #6 where Scan doesn't include the initial value in the transformed stream.

• Fixed an issue where When and Zip transformers would not return the same stream type.

Initial version

• Add BufferWhen transformer
• Add Combine transformer
• Add Debounce transformer
• Add Delay transformer
• Add FlatMap transformer
• Add FlatMapLatest transformer
• Add Merge transformer
• Add Scan transformer
• Add SkipUntil transformer
• Add TakeUntil transformer
• Add When transformer
• Add Zip transformer