[SPARK-7669] Builds against Hadoop 2.6+ get inconsistent curator depend…

This adds a new profile, `hadoop-2.6`, copying over the hadoop-2.4 properties, updating ZK to 3.4.6 and making the curator version a configurable option. That keeps the curator-recipes JAR in sync with that used in hadoop.

There's one more option to consider: making the full curator-client version explicit with its own dependency version. This will pin down the version from hadoop and hive imports

Author: Steve Loughran <stevel@hortonworks.com>

Closes apache#6191 from steveloughran/stevel/SPARK-7669-hadoop-2.6 and squashes the following commits:

e3e281a [Steve Loughran] SPARK-7669 declare the version of curator-client and curator-framework JARs
2901ea9 [Steve Loughran] SPARK-7669 Builds against Hadoop 2.6+ get inconsistent curator dependencies

pom.xml

@@ -130,6 +130,7 @@
     <hbase.artifact>hbase</hbase.artifact>
     <flume.version>1.4.0</flume.version>
     <zookeeper.version>3.4.5</zookeeper.version>
+    <curator.version>2.4.0</curator.version>
     <hive.group>org.spark-project.hive</hive.group>
     <!-- Version used in Maven Hive dependency -->
     <hive.version>0.13.1a</hive.version>
@@ -707,7 +708,7 @@
       <dependency>
         <groupId>org.apache.curator</groupId>
         <artifactId>curator-recipes</artifactId>
-        <version>2.4.0</version>
+        <version>${curator.version}</version>
         <scope>${hadoop.deps.scope}</scope>
         <exclusions>
           <exclusion>
@@ -716,6 +717,16 @@
           </exclusion>
         </exclusions>
       </dependency>
+      <dependency>
+        <groupId>org.apache.curator</groupId>
+        <artifactId>curator-client</artifactId>
+        <version>${curator.version}</version>
+      </dependency>
+      <dependency>
+        <groupId>org.apache.curator</groupId>
+        <artifactId>curator-framework</artifactId>
+        <version>${curator.version}</version>
+      </dependency>
       <dependency>
         <groupId>org.apache.hadoop</groupId>
         <artifactId>hadoop-client</artifactId>
@@ -1679,6 +1690,17 @@
       </properties>
     </profile>
 
+    <profile>
+      <id>hadoop-2.6</id>
+      <properties>
+        <hadoop.version>2.6.0</hadoop.version>
+        <jets3t.version>0.9.3</jets3t.version>
+        <commons.math3.version>3.1.1</commons.math3.version>
+        <zookeeper.version>3.4.6</zookeeper.version>
+        <curator.version>2.6.0</curator.version>
+      </properties>
+    </profile>
+
     <profile>
       <id>yarn</id>
       <modules>
@@ -1709,7 +1731,7 @@
         <dependency>
           <groupId>org.apache.curator</groupId>
           <artifactId>curator-recipes</artifactId>
-          <version>2.4.0</version>
+          <version>${curator.version}</version>
           <exclusions>
             <exclusion>
               <groupId>org.apache.zookeeper</groupId>