Clean-up of Future documentation and small fix-ups.

sdk/lib/async/stream.dart

Index: sdk/lib/async/stream.dart
diff --git a/sdk/lib/async/stream.dart b/sdk/lib/async/stream.dart
index bf7840912d8846ff2cf2b2a7ad3d12d7b3bef68f..ffb65771a350887efe95a0d869e11273a7c06d49 100644
--- a/sdk/lib/async/stream.dart
+++ b/sdk/lib/async/stream.dart
@@ -630,12 +630,12 @@ abstract class Stream<T> {
    *
    * Returns a new stream where each element of this stream is replaced
    * by zero or more data events.
-   * The event values are proveded as an [Iterable] by a call to [convert]
+   * The event values are provided as an [Iterable] by a call to [convert]
    * with the element as argument, and the elements of that iterable is
    * emitted in iteration order.
-   * If calling [convert] throws, or if iteration of the returned values throws,
-   * the error is emitted on the returned stream and iteration ends for that
-   * element of this stream.
+   * If calling [convert] throws, or if the iteration of the returned values
+   * throws, the error is emitted on the returned stream and iteration ends
+   * for that element of this stream.
    *
    * Error events and the done event of this stream are forwarded directly
    * to the returned stream.