Improving Javadoc of Executor impls to be more informative. :-) Matt please check.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@277131 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/helper/DefaultExecutor.java

@@ -25,6 +25,8 @@ import org.apache.tools.ant.BuildException;
 
 /**
  * Default Target executor implementation.
+ * Runs each target individually (including all of its dependencies),
+ * halting immediately upon error.
  * @since Ant 1.6.3
  */
 public class DefaultExecutor implements Executor {

src/main/org/apache/tools/ant/helper/KeepGoingExecutor.java

@@ -25,6 +25,9 @@ import org.apache.tools.ant.BuildException;
 
 /**
  * "Keep-going" Target executor implementation.
+ * Differs from {@link DefaultExecutor} in that a failure in one target does
+ * not halt execution; all targets are attempted, in order. The last failure,
+ * if any, is reported to the caller.
  * @since Ant 1.6.3
  */
 public class KeepGoingExecutor implements Executor {

src/main/org/apache/tools/ant/helper/SingleCheckExecutor.java

@@ -27,6 +27,8 @@ import org.apache.tools.ant.BuildException;
 
 /**
  * "Single-check" Target executor implementation.
+ * Differs from {@link DefaultExecutor} in that the dependencies for all
+ * targets are computed together, so that shared dependencies are run just once.
  * @since Ant 1.6.3
  */
 public class SingleCheckExecutor implements Executor {