[SPARK-7895] [STREAMING] [EXAMPLES] Move Kafka examples from scala-2.10/src to src

Since `spark-streaming-kafka` now is published for both Scala 2.10 and 2.11, we can move `KafkaWordCount` and `DirectKafkaWordCount` from `examples/scala-2.10/src/` to `examples/src/` so that they will appear in `spark-examples-***-jar` for Scala 2.11.

Author: zsxwing <zsxwing@gmail.com>

Closes #6436 from zsxwing/SPARK-7895 and squashes the following commits:

c6052f1 [zsxwing] Update examples/pom.xml
0bcfa87 [zsxwing] Fix the sleep time
b9d1256 [zsxwing] Move Kafka examples from scala-2.10/src to src

examples/pom.xml

@@ -97,6 +97,11 @@
         </exclusion>
       </exclusions>
     </dependency>
+    <dependency>
+      <groupId>org.apache.spark</groupId>
+      <artifactId>spark-streaming-kafka_${scala.binary.version}</artifactId>
+      <version>${project.version}</version>
+    </dependency>
     <dependency>
       <groupId>org.apache.hbase</groupId>
       <artifactId>hbase-testing-util</artifactId>
@@ -392,45 +397,6 @@
         </dependency>
       </dependencies>
     </profile>
-    <profile>
-      <!-- We add a source directory specific to Scala 2.10 since Kafka
-           only works with it -->
-      <id>scala-2.10</id>
-      <activation>
-        <property><name>!scala-2.11</name></property>
-      </activation>
-      <dependencies>
-        <dependency>
-          <groupId>org.apache.spark</groupId>
-          <artifactId>spark-streaming-kafka_${scala.binary.version}</artifactId>
-          <version>${project.version}</version>
-        </dependency>
-      </dependencies>
-      <build>
-        <plugins>
-          <plugin>
-            <groupId>org.codehaus.mojo</groupId>
-            <artifactId>build-helper-maven-plugin</artifactId>
-            <executions>
-              <execution>
-                <id>add-scala-sources</id>
-                <phase>generate-sources</phase>
-                <goals>
-                  <goal>add-source</goal>
-                </goals>
-                <configuration>
-                  <sources>
-                    <source>src/main/scala</source>
-                    <source>scala-2.10/src/main/scala</source>
-                    <source>scala-2.10/src/main/java</source>
-                  </sources>
-                </configuration>
-              </execution>
-            </executions>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
 
     <!-- Profiles that disable inclusion of certain dependencies. -->
     <profile>

examples/scala-2.10/src/main/scala/org/apache/spark/examples/streaming/KafkaWordCount.scala → examples/src/main/scala/org/apache/spark/examples/streaming/KafkaWordCount.scala

@@ -96,7 +96,7 @@ object KafkaWordCountProducer {
         producer.send(message)
       }
 
-      Thread.sleep(100)
+      Thread.sleep(1000)
     }
   }