SPARK-1935: Explicitly add commons-codec 1.5 as a dependency.

Author: Yin Huai <huai@cse.ohio-state.edu>

Closes #889 from yhuai/SPARK-1935 and squashes the following commits:

7d50ef1 [Yin Huai] Explicitly add commons-codec 1.5 as a dependency.

pom.xml

@@ -240,6 +240,11 @@
         <artifactId>commons-lang3</artifactId>
         <version>3.3.2</version>
       </dependency>
+      <dependency>
+	  <groupId>commons-codec</groupId>
+	    <artifactId>commons-codec</artifactId>
+	    <version>1.5</version>
+      </dependency>
       <dependency>
         <groupId>com.google.code.findbugs</groupId>
         <artifactId>jsr305</artifactId>

project/SparkBuild.scala

@@ -348,6 +348,7 @@ object SparkBuild extends Build {
         "org.apache.mesos"           % "mesos"            % "0.18.1" classifier("shaded-protobuf") exclude("com.google.protobuf", "protobuf-java"),
         "commons-net"                % "commons-net"      % "2.2",
         "net.java.dev.jets3t"        % "jets3t"           % jets3tVersion excludeAll(excludeCommonsLogging),
+        "commons-codec"              % "commons-codec"    % "1.5", // Prevent jets3t from including the older version of commons-codec
         "org.apache.derby"           % "derby"            % "10.4.2.0"                     % "test",
         "org.apache.hadoop"          % hadoopClient       % hadoopVersion excludeAll(excludeJBossNetty, excludeAsm, excludeCommonsLogging, excludeSLF4J, excludeOldAsm),
         "org.apache.curator"         % "curator-recipes"  % "2.4.0" excludeAll(excludeJBossNetty),