Spelling and dartdoc references (#91)

* fix a couple of spelling mistakes
* Remove un-referencable doc references
diff --git a/lib/src/handler.dart b/lib/src/handler.dart
index 8ff2a89..811f805 100644
--- a/lib/src/handler.dart
+++ b/lib/src/handler.dart
@@ -12,7 +12,7 @@
 /// filesystem and return it as the body of the [Response].
 ///
 /// A [Handler] which wraps one or more other handlers to perform pre or post
-/// processing is knowns as a "middleware".
+/// processing is known as a "middleware".
 ///
 /// A [Handler] may receive a request directly from an HTTP server or it
 /// may have been touched by other middleware. Similarly the response may be
diff --git a/lib/src/message.dart b/lib/src/message.dart
index 0f13e85..2265120 100644
--- a/lib/src/message.dart
+++ b/lib/src/message.dart
@@ -106,7 +106,7 @@
   /// [headers].
   ///
   /// If [headers] doesn't have a Content-Type header or it specifies an
-  /// encoding that [dart:convert] doesn't support, this will be `null`.
+  /// encoding that `dart:convert` doesn't support, this will be `null`.
   Encoding get encoding {
     var contentType = _contentType;
     if (contentType == null) return null;
diff --git a/lib/src/server.dart b/lib/src/server.dart
index e3c216b..d48ba51 100644
--- a/lib/src/server.dart
+++ b/lib/src/server.dart
@@ -10,7 +10,7 @@
 ///
 /// [adapter]: https://github.com/dart-lang/shelf#adapters
 ///
-/// The most basic definiton of "adapter" includes any function that passes
+/// The most basic definition of "adapter" includes any function that passes
 /// incoming requests to a [Handler] and passes its responses to some external
 /// client. However, in practice, most adapters are also *servers*—that is,
 /// they're serving requests that are made to a certain well-known URL.
@@ -30,7 +30,7 @@
   ///
   /// Requests to this URL or any URL beneath it are handled by the handler
   /// passed to [mount]. If [mount] hasn't yet been called, the requests wait
-  /// until it is. If [close] has been called, [handler] will not be invoked;
+  /// until it is. If [close] has been called, the handler will not be invoked;
   /// otherwise, the behavior is implementation-dependent.
   Uri get url;