Add missing newline after Actual value in fail message.
Remove the BasMatcher class; it made some sense when we had both 'interface'
and 'class' but adds no value now.
Fix a comment in the CustomMatcher documentation.
Fix tests affected by these changes.

R=sigmund@google.com

Review URL: https://codereview.chromium.org//18442002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@25356 260f80e4-7a28-3924-810f-c04153c831b5

pkgs/watcher/test/utils.dart

diff --git a/pkgs/watcher/test/utils.dart b/pkgs/watcher/test/utils.dart
index 3f5844b..5053b76 100644
--- a/pkgs/watcher/test/utils.dart
+++ b/pkgs/watcher/test/utils.dart
@@ -176,7 +176,7 @@
 }
 
 /// A [Matcher] for [WatchEvent]s.
-class _ChangeMatcher extends BaseMatcher {
+class _ChangeMatcher extends Matcher {
   /// The expected change.
   final ChangeType type;