SPARK-1862: Support for MapR in the Maven build.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #803 from pwendell/mapr-support and squashes the following commits:

8df60e4 [Patrick Wendell] SPARK-1862: Support for MapR in the Maven build.

pom.xml

@@ -123,6 +123,7 @@
     <protobuf.version>2.4.1</protobuf.version>
     <yarn.version>${hadoop.version}</yarn.version>
     <hbase.version>0.94.6</hbase.version>
+    <zookeeper.version>3.4.5</zookeeper.version>
     <hive.version>0.12.0</hive.version>
     <parquet.version>1.4.3</parquet.version>
     <jblas.version>1.2.3</jblas.version>
@@ -194,6 +195,17 @@
         <enabled>false</enabled>
       </snapshots>
     </repository>
+    <repository>
+      <id>mapr-repo</id>
+      <name>MapR Repository</name>
+      <url>http://repository.mapr.com/maven</url>
+      <releases>
+        <enabled>true</enabled>
+      </releases>
+      <snapshots>
+        <enabled>false</enabled>
+      </snapshots>
+    </repository>
   </repositories>
 
   <dependencyManagement>
@@ -490,6 +502,14 @@
             <groupId>commons-logging</groupId>
             <artifactId>commons-logging</artifactId>
           </exclusion>
+          <exclusion>
+            <groupId>org.mortbay.jetty</groupId>
+            <artifactId>servlet-api-2.5</artifactId>
+          </exclusion>
+          <exclusion>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+          </exclusion>
         </exclusions>
       </dependency>
       <dependency>
@@ -979,6 +999,20 @@
       </modules>
     </profile>
 
+    <profile>
+      <id>mapr</id>
+      <activation>
+        <activeByDefault>false</activeByDefault>
+      </activation>
+      <properties>
+        <hadoop.version>1.0.3-mapr-3.0.3</hadoop.version>
+        <yarn.version>2.3.0-mapr-4.0.0-beta</yarn.version>
+        <hbase.version>0.94.17-mapr-1403</hbase.version>
+        <hbase.version>0.94.17-mapr-1403</hbase.version>
+        <zookeeper.version>3.4.5-mapr-1401</zookeeper.version>
+      </properties>
+    </profile>
+
     <!-- Build without Hadoop dependencies that are included in some runtime environments. -->
     <profile>
       <id>hadoop-provided</id>
@@ -1024,7 +1058,7 @@
         <dependency>
           <groupId>org.apache.zookeeper</groupId>
           <artifactId>zookeeper</artifactId>
-          <version>3.4.5</version>
+          <version>${zookeeper.version}</version>
           <scope>provided</scope>
         </dependency>
       </dependencies>