[SPARK-7042] [BUILD] use the standard akka artifacts with hadoop-2.x

Both akka 2.3.x and hadoop-2.x use protobuf 2.5 so only hadoop-1 build needs
custom 2.3.4-spark akka version that shades protobuf-2.5

This change also updates akka version (for hadoop-2.x profiles only) to the
latest 2.3.11 as akka-zeromq_2.11 is not available for akka 2.3.4.

This partially fixes SPARK-7042 (for hadoop-2.x builds)

Author: Konstantin Shaposhnikov <Konstantin.Shaposhnikov@sc.com>

Closes #6492 from kostya-sh/SPARK-7042 and squashes the following commits:

dc195b0 [Konstantin Shaposhnikov] [SPARK-7042] [BUILD] use the standard akka artifacts with hadoop-2.x

pom.xml

@@ -114,8 +114,8 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-    <akka.group>org.spark-project.akka</akka.group>
-    <akka.version>2.3.4-spark</akka.version>
+    <akka.group>com.typesafe.akka</akka.group>
+    <akka.version>2.3.11</akka.version>
     <java.version>1.6</java.version>
     <sbt.project.name>spark</sbt.project.name>
     <mesos.version>0.21.1</mesos.version>
@@ -1670,6 +1670,8 @@
         <hbase.version>0.98.7-hadoop1</hbase.version>
         <avro.mapred.classifier>hadoop1</avro.mapred.classifier>
         <codehaus.jackson.version>1.8.8</codehaus.jackson.version>
+        <akka.group>org.spark-project.akka</akka.group>
+        <akka.version>2.3.4-spark</akka.version>
       </properties>
     </profile>