Version 0.3

Beyond a few minor bug fixes:

• Future streams. Like Futures, but handles a stream of values (SPSC).
• Formalize expected usage pattern: Futures assume that it's more likely than not that a callback will have been attached by the time the value become available
• mostly lockless: All operations on regular futures are now lockless. Future streams still have a bit of locking during initialization.
• Promises now can be filled before a future is created from them.

Feature	status
Future<>	Ready for review
Promise<>	Ready for review
Future_stream<>	Feature Complete
Future_promise<>	Feature Complete

What's missing for a v1.0:

• Completed documentation
• Test coverage on streams