0.10-rc: Mutex & Kotlin RC

• Switched to Kotlin version 1.1.0-rc-91.
• Mutex synchronization primitive is introduced.
• buildChannel is renamed to produce, old name is deprecated.
• Job.onCompletion is renamed to Job.invokeOnCompletion, old name is deprecated.
• delay implementation in Swing, JavaFx, and scheduled executors is fixed to avoid an extra dispatch.
• CancellableContinuation.resumeUndispatched is introduced to make this efficient implementation possible.
• Remove unnecessary creation of CancellationException to improve performance, plus other performance improvements.
• Suppress deprecated and internal APIs from docs.
• Better docs at top level with categorized summary of classes and functions.

0.8-beta: async and other maintanance

• defer coroutine builder is renamed to async.
• lazyDefer is deprecated, async has an optional start parameter instead.
• LazyDeferred interface is deprecated, lazy start functionality is integrated into Job interface.
• launch has an optional start parameter for lazily started coroutines.
• Job.start and Job.isCompleted are introduced.
• Deferred.isCompletedExceptionally and Deferred.isCancelled are introduced.
• Job.getInactiveCancellationException is renamed to getCompletionException.
• Job.join is now a member function.
• Internal JobSupport state machine is enhanced to support new (not-started-yet) state.
  So, lazy coroutines do not need a separate state variable to track their started/not-started (new/active) status.
• Exception transparency in Job.cancel (original cause is rethrown).
• Clarified possible states for Job/CancellableContinuation/Deferred in docs.
• Example on async-style functions and links to API reference site from coroutines guide.

0.7-beta: Channels

• Buffered and unbuffered channels are introduced: Channel, SendChannel, and ReceiveChannel interfaces,
  RendezvousChannel and ArrayChannel implementations, Channel() factory function and buildChannel{}
  coroutines builder.
• Here context is renamed to Unconfined (the old name is deprecated).
• A guide on coroutines is expanded: sections on contexts and channels.

0.6-beta: for Kotlin 1.1.0-beta-38

• Switched to Kotlin version 1.1.0-beta-38.
• A guide on coroutines is expanded.

0.5-beta: for Kotlin 1.1.0-beta-22

• Switched to Kotlin version 1.1.0-beta-22 (republished version).
• Removed currentCoroutineContext and related thread-locals without replacement.
  Explicitly pass coroutine context around if needed.
• lazyDefer(context) {...} coroutine builder and LazyDeferred interface are introduced.
• The default behaviour of all coroutine dispatchers is changed to always schedule execution of new coroutine
  for later in this thread or thread pool. Correspondingly, CoroutineDispatcher.isDispatchNeeded function
  has a default implementation that returns true.
• NonCancellable context is introduced.
• Performance optimizations for cancellable continuations (fewer objects created).
• A guide on coroutines is added.

0.4-beta: for Kotlin 1.1.0-beta-18

• Switched to Kotlin version 1.1.0-beta-18 (republished version).
• CoroutineDispatcher methods now have context parameter.
• Introduced CancellableContinuation.isCancelled
• Introduced EventLoop dispatcher and made it a default for runBlocking { ... }
• Introduced CoroutineScope interface with isActive and context properties;
  standard coroutine builders include it as receiver for convenience.
• Introduced Executor.toCoroutineDispatcher() extension.
• Delay scheduler thread is not daemon anymore, but times out automatically.
• Debugging facilities in newCoroutineContext can be explicitly disabled with -Dkotlinx.coroutines.debug=off.
• xxx-test files are renamed to xxx-example for clarity.
• Fixed NPE in Job implementation when starting coroutine with already cancelled parent job.
• Support cancellation in kotlinx-coroutines-nio module

0.3-beta: for Kotlin 1.1.0-beta-17

Fixed exception unwrapping in fast-path of CompletableFuture.await()